diff --git a/packages/@n8n/backend-services/eslint.config.mjs b/packages/@n8n/backend-services/eslint.config.mjs
index c9c5ad26bf3..766d97365e7 100644
--- a/packages/@n8n/backend-services/eslint.config.mjs
+++ b/packages/@n8n/backend-services/eslint.config.mjs
@@ -21,6 +21,10 @@ export default defineConfig(
 							rule: 'no-unsealed-workflow-entity-write',
 							message: 'Route the write through a token-gated `WorkflowRepository` method.',
 						},
+						{
+							rule: 'no-unsealed-credentials-entity-write',
+							message: 'Route the write through a token-gated `CredentialsRepository` method.',
+						},
 					],
 				},
 			],
diff --git a/packages/@n8n/backend-services/oxlint.config.mts b/packages/@n8n/backend-services/oxlint.config.mts
index c9ade75b8f7..a6060889413 100644
--- a/packages/@n8n/backend-services/oxlint.config.mts
+++ b/packages/@n8n/backend-services/oxlint.config.mts
@@ -21,6 +21,10 @@ export default defineConfig({
 						rule: 'no-unsealed-workflow-entity-write',
 						message: 'Route the write through a token-gated `WorkflowRepository` method.',
 					},
+					{
+						rule: 'no-unsealed-credentials-entity-write',
+						message: 'Route the write through a token-gated `CredentialsRepository` method.',
+					},
 				],
 			},
 		],
diff --git a/packages/@n8n/eslint-config/src/plugin.ts b/packages/@n8n/eslint-config/src/plugin.ts
index 0bb5f8b8c58..785572340b8 100644
--- a/packages/@n8n/eslint-config/src/plugin.ts
+++ b/packages/@n8n/eslint-config/src/plugin.ts
@@ -18,8 +18,9 @@ export const localRulesPlugin = {
 				'n8n-local-rules': plugin,
 			},
 			rules: {
-				// Seals WorkflowEntity node writes to the token-gated repository methods.
+				// Seal entity content writes to the token-gated repository methods.
 				'n8n-local-rules/no-unsealed-workflow-entity-write': 'error',
+				'n8n-local-rules/no-unsealed-credentials-entity-write': 'error',
 				'n8n-local-rules/no-uncaught-json-parse': 'error',
 				'n8n-local-rules/no-json-parse-json-stringify': 'error',
 				'n8n-local-rules/no-unneeded-backticks': 'error',
diff --git a/packages/@n8n/eslint-config/src/rules/index.ts b/packages/@n8n/eslint-config/src/rules/index.ts
index 9c61a2eaeda..923b82624ed 100644
--- a/packages/@n8n/eslint-config/src/rules/index.ts
+++ b/packages/@n8n/eslint-config/src/rules/index.ts
@@ -28,6 +28,7 @@ import { NoRestrictedSleepImportRule } from './no-restricted-sleep-import.js';
 import { NoRepositoryInPublicApiHandlerRule } from './no-repository-in-public-api-handler.js';
 import { RequirePublicApiControllerRule } from './require-public-api-controller.js';
 import { NoUnsealedWorkflowEntityWriteRule } from './no-unsealed-workflow-entity-write.js';
+import { NoUnsealedCredentialsEntityWriteRule } from './no-unsealed-credentials-entity-write.js';
 import { RequireEscapedQueryValuesRule } from './require-escaped-query-values.js';
 import { NoOnLeaderTakeoverRule } from './no-on-leader-takeover.js';
 import { NoEncryptionGuardrailDisableRule } from './no-encryption-guardrail-disable.js';
@@ -62,6 +63,7 @@ export const rules = {
 	'no-repository-in-public-api-handler': NoRepositoryInPublicApiHandlerRule,
 	'require-public-api-controller': RequirePublicApiControllerRule,
 	'no-unsealed-workflow-entity-write': NoUnsealedWorkflowEntityWriteRule,
+	'no-unsealed-credentials-entity-write': NoUnsealedCredentialsEntityWriteRule,
 	'require-escaped-query-values': RequireEscapedQueryValuesRule,
 	'no-on-leader-takeover': NoOnLeaderTakeoverRule,
 	'no-encryption-guardrail-disable': NoEncryptionGuardrailDisableRule,
diff --git a/packages/@n8n/eslint-config/src/rules/no-unsealed-credentials-entity-write.test.ts b/packages/@n8n/eslint-config/src/rules/no-unsealed-credentials-entity-write.test.ts
new file mode 100644
index 00000000000..d619cdd0cce
--- /dev/null
+++ b/packages/@n8n/eslint-config/src/rules/no-unsealed-credentials-entity-write.test.ts
@@ -0,0 +1,95 @@
+import { RuleTester } from '@typescript-eslint/rule-tester';
+
+import { NoUnsealedCredentialsEntityWriteRule } from './no-unsealed-credentials-entity-write.js';
+
+const ruleTester = new RuleTester();
+const errors = [{ messageId: 'unsealedWrite' as const }];
+
+ruleTester.run('no-unsealed-credentials-entity-write', NoUnsealedCredentialsEntityWriteRule, {
+	valid: [
+		// An OAuth token refresh writes ciphertext, never the type.
+		'credentialsRepository.update(id, { data });',
+		'credentialsRepository.update(id, { data, updatedAt });',
+		'credentialsRepository.update(id);',
+		// The sanctioned, token-gated write methods.
+		'credentialsRepository.updateContent(id, { type }, ctx);',
+		'credentialsRepository.createContent(credential, ctx);',
+		'credentialsRepository.saveInstanceCredential(credential, ctx);',
+		// Reads and existence changes are out of the type seal's scope.
+		'credentialsRepository.delete(id);',
+		'credentialsRepository.existsBy({ id });',
+		"manager.query('DELETE FROM credentials_entity WHERE id = ?');",
+		"manager.query('SELECT data FROM credentials_entity WHERE id = ?');",
+		// Anchored, so a sibling repository stays out.
+		'sharedCredentialsRepository.save(sharedCredential);',
+		'credentialDependencyRepository.save(dependency);',
+		// A different entity.
+		'workflowRepository.save(workflow);',
+		'manager.save(WorkflowEntity, workflow);',
+		"manager.query('UPDATE workflow_entity SET nodes = ?');",
+		{ code: 'credentialsRepository.save(credential);', filename: '/src/example.test.ts' },
+		{
+			code: 'credentialsRepository.save(credential);',
+			filename: '/repositories/credentials.repository.ts',
+		},
+		{
+			code: 'credentialsRepository.save(credential);',
+			filename: '/packages/@n8n/backend-test-utils/src/db/credentials.ts',
+		},
+		// A database migration owns its table.
+		{
+			code: 'credentialsRepository.save(credential);',
+			filename: '/packages/@n8n/db/src/migrations/common/1700000000000-Foo.ts',
+		},
+		{
+			code: 'credentialsRepository.save(credential);',
+			filename: '/packages/@n8n/engine/src/database/migrations/1700000000000-Foo.ts',
+		},
+	],
+	invalid: [
+		{ code: 'credentialsRepository.save(credential);', errors },
+		{ code: 'this.credentialsRepository.save(credential);', errors },
+		{ code: "this.credentialsRepo.update(id, { type: 'slackApi' });", errors },
+		{ code: "credentialsRepository['save'](credential);", errors },
+		{ code: 'credentialRepo.insert(credential);', errors },
+		{ code: 'Container.get(CredentialsRepository).save(credential);', errors },
+		{ code: 'dataSource.getRepository(CredentialsEntity).save(credential);', errors },
+		{ code: 'manager.getRepository(CredentialsEntity).insert(credential);', errors },
+		{ code: "manager.getRepository(CredentialsEntity).upsert(credential, ['id']);", errors },
+		{ code: "manager.getRepository(CredentialsEntity).update(id, { type: 'slackApi' });", errors },
+		{ code: "manager.getRepository('credentials_entity').save(credential);", errors },
+		{ code: 'credentialsRepository?.save(credential);', errors },
+		{ code: "credentialsRepository.update(id, { type: 'slackApi' });", errors },
+		{ code: "credentialsRepository.update(id, { 'type': 'slackApi' });", errors },
+		{ code: 'manager.save(CredentialsEntity, credential);', errors },
+		{ code: "manager.upsert(CredentialsEntity, credential, ['id']);", errors },
+		{ code: "manager.update(CredentialsEntity, id, { type: 'slackApi' });", errors },
+		{ code: "manager.update<CredentialsEntity>(id, { type: 'slackApi' });", errors },
+		// A call in the receiver must not hide the type argument.
+		{ code: "dataSource.manager.update<CredentialsEntity>(id, { type: 'slackApi' });", errors },
+		{
+			code: "container.get(DataSource).manager.update<CredentialsEntity>(id, { type: 'slackApi' });",
+			errors,
+		},
+		{ code: 'queryBuilder.insert().into(CredentialsEntity);', errors },
+		{
+			code: "manager.createQueryBuilder().update(CredentialsEntity).set({ type: 'slackApi' });",
+			errors,
+		},
+		{
+			code: "credentialsRepository.createQueryBuilder().update().set({ type: 'slackApi' });",
+			errors,
+		},
+		{ code: "manager.query('UPDATE credentials_entity SET type = ?');", errors },
+		{ code: 'manager.query(`INSERT INTO credentials_entity (type) VALUES (?)`);', errors },
+		{ code: 'manager.query(`UPDATE ${prefix}credentials_entity SET type = ?`);', errors },
+		{ code: "manager.query('UPDATE public.credentials_entity SET type = ?');", errors },
+		// A folder merely named `migrations` is not a database migration.
+		{
+			code: 'credentialsRepository.save(credential);',
+			filename: '/packages/cli/src/modules/breaking-changes/migrations/foo.migration.ts',
+			errors,
+		},
+		{ code: 'manager.query(`UPDATE "public"."credentials_entity" SET type = ?`);', errors },
+	],
+});
diff --git a/packages/@n8n/eslint-config/src/rules/no-unsealed-credentials-entity-write.ts b/packages/@n8n/eslint-config/src/rules/no-unsealed-credentials-entity-write.ts
new file mode 100644
index 00000000000..29f5aeda152
--- /dev/null
+++ b/packages/@n8n/eslint-config/src/rules/no-unsealed-credentials-entity-write.ts
@@ -0,0 +1,15 @@
+import { createUnsealedEntityWriteRule } from './unsealed-entity-write.factory.js';
+
+export const NoUnsealedCredentialsEntityWriteRule = createUnsealedEntityWriteRule({
+	entityName: 'CredentialsEntity',
+	tableName: 'credentials_entity',
+	repositoryName: 'CredentialsRepository',
+	// A sibling like `sharedCredentialsRepository` stays out because the match is anchored.
+	repositoryReceiver: /^(?:credential|credentials)Repo(?:sitory)?$/i,
+	repositoryFile: /[\\/]repositories[\\/]credentials\.repository\.ts$/,
+	// `type` is the only field the credential policy check reads, so a data-only write
+	// (an OAuth token refresh) stays clean.
+	policedKey: 'type',
+	description: 'Route credential type writes through policy-cleared repository methods.',
+	message: 'Route CredentialsEntity type writes through a policy-cleared repository method.',
+});
diff --git a/packages/@n8n/eslint-config/src/rules/no-unsealed-workflow-entity-write.test.ts b/packages/@n8n/eslint-config/src/rules/no-unsealed-workflow-entity-write.test.ts
index d3015285282..c3560a9d42b 100644
--- a/packages/@n8n/eslint-config/src/rules/no-unsealed-workflow-entity-write.test.ts
+++ b/packages/@n8n/eslint-config/src/rules/no-unsealed-workflow-entity-write.test.ts
@@ -21,6 +21,11 @@ ruleTester.run('no-unsealed-workflow-entity-write', NoUnsealedWorkflowEntityWrit
 			code: 'workflowRepository.save(workflow);',
 			filename: '/packages/@n8n/backend-test-utils/src/db/workflows.ts',
 		},
+		// A database migration owns its table.
+		{
+			code: 'workflowRepository.save(workflow);',
+			filename: '/packages/@n8n/db/src/migrations/common/1700000000000-Foo.ts',
+		},
 	],
 	invalid: [
 		{ code: 'workflowRepository.save(workflow);', errors },
@@ -41,6 +46,11 @@ ruleTester.run('no-unsealed-workflow-entity-write', NoUnsealedWorkflowEntityWrit
 		{ code: "manager.upsert(WorkflowEntity, workflow, ['id']);", errors },
 		{ code: 'manager.update(WorkflowEntity, id, { nodes: [] });', errors },
 		{ code: 'manager.update<WorkflowEntity>(id, { nodes: [] });', errors },
+		// A call in the receiver must not hide the type argument.
+		{
+			code: 'container.get(DataSource).manager.update<WorkflowEntity>(id, { nodes: [] });',
+			errors,
+		},
 		{ code: 'queryBuilder.insert().into(WorkflowEntity);', errors },
 		{
 			code: 'manager.createQueryBuilder().update(WorkflowEntity).set({ nodes: [] });',
@@ -56,5 +66,12 @@ ruleTester.run('no-unsealed-workflow-entity-write', NoUnsealedWorkflowEntityWrit
 		{ code: 'manager.query(`UPDATE\\x20workflow_entity SET nodes = ?`);', errors },
 		{ code: "manager.query('UPDATE public.workflow_entity SET nodes = ?');", errors },
 		{ code: 'manager.query(`UPDATE "public"."workflow_entity" SET nodes = ?`);', errors },
+		// A folder merely named `migrations` is not a database migration: the node
+		// migrations under breaking-changes rewrite workflow content at runtime.
+		{
+			code: 'workflowRepository.save(workflow);',
+			filename: '/packages/cli/src/modules/breaking-changes/migrations/foo.migration.ts',
+			errors,
+		},
 	],
 });
diff --git a/packages/@n8n/eslint-config/src/rules/no-unsealed-workflow-entity-write.ts b/packages/@n8n/eslint-config/src/rules/no-unsealed-workflow-entity-write.ts
index 8a34c3600b0..5b8557aeb66 100644
--- a/packages/@n8n/eslint-config/src/rules/no-unsealed-workflow-entity-write.ts
+++ b/packages/@n8n/eslint-config/src/rules/no-unsealed-workflow-entity-write.ts
@@ -1,204 +1,12 @@
-import { ESLintUtils } from '@typescript-eslint/utils';
+import { createUnsealedEntityWriteRule } from './unsealed-entity-write.factory.js';
 
-const NON_RUNTIME_FILE =
-	/(\.(test|spec)\.ts$)|([\\/]__tests__[\\/])|([\\/]test[\\/])|([\\/]migrations[\\/])|([\\/]backend-test-utils[\\/])/;
-const WORKFLOW_REPOSITORY_FILE = /[\\/]repositories[\\/]workflow\.repository\.ts$/;
-const WRITE_METHODS = new Set(['save', 'insert', 'upsert']);
-const RAW_WORKFLOW_WRITE =
-	/\b(?:UPDATE|INSERT\s+INTO)\s+(?:(?:"?\w+"?)\s*\.\s*)?["'`]?\w*workflow_entity["'`]?(?=\s|\(|$)/i;
-const WORKFLOW_REPOSITORY_NAME = /^(?:workflow|workflows)Repo(?:sitory)?$/i;
-
-type SyntaxNode = {
-	type: string;
-	name?: string;
-	value?: unknown;
-	computed?: boolean;
-	property?: SyntaxNode;
-	object?: SyntaxNode;
-	expression?: SyntaxNode;
-	callee?: SyntaxNode;
-	arguments?: SyntaxNode[];
-	properties?: Array<{
-		type: string;
-		computed?: boolean;
-		key?: SyntaxNode;
-	}>;
-};
-
-const unwrapChain = (node: SyntaxNode): SyntaxNode =>
-	node.type === 'ChainExpression' && node.expression ? node.expression : node;
-
-const memberName = (node: SyntaxNode) => {
-	if (!node.property) return undefined;
-	if (!node.computed && node.property.type === 'Identifier') return node.property.name;
-	if (
-		node.computed &&
-		node.property.type === 'Literal' &&
-		typeof node.property.value === 'string'
-	) {
-		return node.property.value;
-	}
-	return undefined;
-};
-
-const targetsWorkflowEntity = (node: SyntaxNode | undefined) =>
-	node !== undefined &&
-	((node.type === 'Identifier' && node.name === 'WorkflowEntity') ||
-		(node.type === 'Literal' &&
-			(node.value === 'WorkflowEntity' || node.value === 'workflow_entity')));
-
-const targetsWorkflowRepositoryClass = (node: SyntaxNode | undefined) =>
-	node?.type === 'Identifier' && node.name === 'WorkflowRepository';
-
-const isWorkflowRepository = (node: SyntaxNode): boolean => {
-	const target = unwrapChain(node);
-	if (target.type === 'Identifier') return WORKFLOW_REPOSITORY_NAME.test(target.name ?? '');
-	if (target.type === 'MemberExpression') {
-		return WORKFLOW_REPOSITORY_NAME.test(memberName(target) ?? '');
-	}
-	if (target.type !== 'CallExpression' || !target.callee) return false;
-	const callee = unwrapChain(target.callee);
-	return (
-		callee.type === 'MemberExpression' &&
-		((memberName(callee) === 'get' && targetsWorkflowRepositoryClass(target.arguments?.[0])) ||
-			(memberName(callee) === 'getRepository' && targetsWorkflowEntity(target.arguments?.[0])))
-	);
-};
-
-const hasNodes = (node: SyntaxNode) =>
-	node.type === 'ObjectExpression' &&
-	(node.properties ?? []).some((property) => {
-		if (property.type === 'SpreadElement' || !property.key) return false;
-		if (!property.computed && property.key.type === 'Identifier') {
-			return property.key.name === 'nodes';
-		}
-		return property.key.type === 'Literal' && property.key.value === 'nodes';
-	});
-
-const isWorkflowQueryBuilder = (node: SyntaxNode): boolean => {
-	const call = unwrapChain(node);
-	if (call.type !== 'CallExpression' || !call.callee) return false;
-	const callee = unwrapChain(call.callee);
-	if (callee.type !== 'MemberExpression' || !callee.object) return false;
-	const method = memberName(callee);
-	if (method === 'createQueryBuilder') return isWorkflowRepository(callee.object);
-	if (method !== 'update') return false;
-	return (
-		targetsWorkflowEntity(call.arguments?.[0]) ||
-		(call.arguments?.length === 0 && isWorkflowQueryBuilder(callee.object))
-	);
-};
-
-export const NoUnsealedWorkflowEntityWriteRule = ESLintUtils.RuleCreator.withoutDocs({
-	meta: {
-		type: 'problem',
-		docs: {
-			description: 'Route workflow content writes through policy-cleared repository methods.',
-		},
-		messages: {
-			unsealedWrite:
-				'Route WorkflowEntity content writes through a policy-cleared repository method.',
-		},
-		schema: [],
-	},
-	defaultOptions: [],
-	create(context) {
-		if (
-			NON_RUNTIME_FILE.test(context.filename) ||
-			WORKFLOW_REPOSITORY_FILE.test(context.filename)
-		) {
-			return {};
-		}
-
-		return {
-			CallExpression(node) {
-				const callee = unwrapChain(node.callee as never);
-				if (callee.type !== 'MemberExpression' || !callee.object) return;
-				const method = memberName(callee);
-				if (!method) return;
-
-				if (WRITE_METHODS.has(method) && isWorkflowRepository(callee.object)) {
-					context.report({ node, messageId: 'unsealedWrite' });
-					return;
-				}
-
-				const secondArgument = node.arguments[1];
-				if (
-					method === 'update' &&
-					isWorkflowRepository(callee.object) &&
-					secondArgument !== undefined &&
-					secondArgument.type !== 'SpreadElement' &&
-					hasNodes(secondArgument as never)
-				) {
-					context.report({ node, messageId: 'unsealedWrite' });
-					return;
-				}
-
-				const callPrefix = context.sourceCode.getText(node).split('(', 1)[0];
-				const hasWorkflowTypeArgument = /<[^>]*\bWorkflowEntity\b[^>]*>/.test(callPrefix);
-				const explicitWorkflowTarget = targetsWorkflowEntity(node.arguments[0] as never);
-				const updatePayload = explicitWorkflowTarget ? node.arguments[2] : node.arguments[1];
-				if (
-					method === 'update' &&
-					(explicitWorkflowTarget || hasWorkflowTypeArgument) &&
-					updatePayload !== undefined &&
-					updatePayload.type !== 'SpreadElement' &&
-					hasNodes(updatePayload as never)
-				) {
-					context.report({ node, messageId: 'unsealedWrite' });
-					return;
-				}
-
-				const queryBuilderText = callee.object
-					? context.sourceCode.getText(callee.object as never)
-					: '';
-				if (
-					method === 'set' &&
-					node.arguments[0]?.type !== 'SpreadElement' &&
-					hasNodes(node.arguments[0] as never) &&
-					(isWorkflowQueryBuilder(callee.object) ||
-						/update\s*<[^>]*\bWorkflowEntity\b[^>]*>/.test(queryBuilderText))
-				) {
-					context.report({ node, messageId: 'unsealedWrite' });
-					return;
-				}
-
-				if (
-					['save', 'insert', 'upsert'].includes(method) &&
-					node.arguments[0]?.type !== 'SpreadElement' &&
-					targetsWorkflowEntity(node.arguments[0] as never)
-				) {
-					context.report({ node, messageId: 'unsealedWrite' });
-					return;
-				}
-
-				if (
-					method === 'into' &&
-					node.arguments[0]?.type !== 'SpreadElement' &&
-					targetsWorkflowEntity(node.arguments[0] as never)
-				) {
-					context.report({ node, messageId: 'unsealedWrite' });
-					return;
-				}
-
-				for (const argument of node.arguments) {
-					if (
-						argument.type === 'Literal' &&
-						typeof argument.value === 'string' &&
-						RAW_WORKFLOW_WRITE.test(argument.value)
-					) {
-						context.report({ node: argument, messageId: 'unsealedWrite' });
-					}
-					if (
-						argument.type === 'TemplateLiteral' &&
-						RAW_WORKFLOW_WRITE.test(
-							argument.quasis.map((quasi) => quasi.value.cooked ?? quasi.value.raw).join(''),
-						)
-					) {
-						context.report({ node: argument, messageId: 'unsealedWrite' });
-					}
-				}
-			},
-		};
-	},
+export const NoUnsealedWorkflowEntityWriteRule = createUnsealedEntityWriteRule({
+	entityName: 'WorkflowEntity',
+	tableName: 'workflow_entity',
+	repositoryName: 'WorkflowRepository',
+	repositoryReceiver: /^(?:workflow|workflows)Repo(?:sitory)?$/i,
+	repositoryFile: /[\\/]repositories[\\/]workflow\.repository\.ts$/,
+	policedKey: 'nodes',
+	description: 'Route workflow content writes through policy-cleared repository methods.',
+	message: 'Route WorkflowEntity content writes through a policy-cleared repository method.',
 });
diff --git a/packages/@n8n/eslint-config/src/rules/unsealed-entity-write.factory.ts b/packages/@n8n/eslint-config/src/rules/unsealed-entity-write.factory.ts
new file mode 100644
index 00000000000..1b36a9b33d1
--- /dev/null
+++ b/packages/@n8n/eslint-config/src/rules/unsealed-entity-write.factory.ts
@@ -0,0 +1,252 @@
+import { ESLintUtils } from '@typescript-eslint/utils';
+
+const NON_RUNTIME_FILE =
+	/(\.(test|spec)\.ts$)|([\\/]__tests__[\\/])|([\\/]test[\\/])|([\\/]backend-test-utils[\\/])/;
+
+// A database migration owns its table, so it writes entities directly. Only those
+// directories are exempt: `cli/src/modules/breaking-changes/migrations` holds node
+// migrations, which are runtime code that rewrites workflow content.
+const DATABASE_MIGRATION_FILE = /[\\/](?:db[\\/]src|database)[\\/]migrations[\\/]/;
+const WRITE_METHODS = new Set(['save', 'insert', 'upsert']);
+
+export type SealedEntityWriteConfig = {
+	/** The entity class the seal governs, e.g. `WorkflowEntity`. */
+	entityName: string;
+	/** The table behind it, to catch a write built as raw SQL. */
+	tableName: string;
+	/** The repository that owns the token-gated write methods, e.g. `WorkflowRepository`. */
+	repositoryName: string;
+	/** The repository under any injected name. Anchor it so siblings stay out. */
+	repositoryReceiver: RegExp;
+	/** The one file allowed to write the table directly. */
+	repositoryFile: RegExp;
+	/** The one payload key the policy check reads, e.g. `nodes`. */
+	policedKey: string;
+	/** `meta.docs.description`. */
+	description: string;
+	/** The report message. */
+	message: string;
+};
+
+type SyntaxNode = {
+	type: string;
+	name?: string;
+	value?: unknown;
+	computed?: boolean;
+	property?: SyntaxNode;
+	object?: SyntaxNode;
+	expression?: SyntaxNode;
+	callee?: SyntaxNode;
+	arguments?: SyntaxNode[];
+	properties?: Array<{
+		type: string;
+		computed?: boolean;
+		key?: SyntaxNode;
+	}>;
+};
+
+const unwrapChain = (node: SyntaxNode): SyntaxNode =>
+	node.type === 'ChainExpression' && node.expression ? node.expression : node;
+
+const memberName = (node: SyntaxNode) => {
+	if (!node.property) return undefined;
+	if (!node.computed && node.property.type === 'Identifier') return node.property.name;
+	if (
+		node.computed &&
+		node.property.type === 'Literal' &&
+		typeof node.property.value === 'string'
+	) {
+		return node.property.value;
+	}
+	return undefined;
+};
+
+/**
+ * Builds a rule that routes one entity's content writes through its policy-cleared
+ * repository methods. Purely syntactic, so Oxlint can execute it as a jsPlugin rule:
+ * a hoisted payload, an aliased receiver and a target built at runtime all stay out of
+ * reach. The `assertClearedFor` gate in the repository is the enforcing half.
+ */
+export const createUnsealedEntityWriteRule = (config: SealedEntityWriteConfig) => {
+	const {
+		entityName,
+		tableName,
+		repositoryName,
+		repositoryReceiver,
+		repositoryFile,
+		policedKey,
+		description,
+		message,
+	} = config;
+
+	const rawWrite = new RegExp(
+		`\\b(?:UPDATE|INSERT\\s+INTO)\\s+(?:(?:"?\\w+"?)\\s*\\.\\s*)?["'\`]?\\w*${tableName}["'\`]?(?=\\s|\\(|$)`,
+		'i',
+	);
+
+	const targetsEntity = (node: SyntaxNode | undefined) =>
+		node !== undefined &&
+		((node.type === 'Identifier' && node.name === entityName) ||
+			(node.type === 'Literal' && (node.value === entityName || node.value === tableName)));
+
+	const targetsRepositoryClass = (node: SyntaxNode | undefined) =>
+		node?.type === 'Identifier' && node.name === repositoryName;
+
+	const isRepository = (node: SyntaxNode): boolean => {
+		const target = unwrapChain(node);
+		if (target.type === 'Identifier') return repositoryReceiver.test(target.name ?? '');
+		if (target.type === 'MemberExpression') {
+			return repositoryReceiver.test(memberName(target) ?? '');
+		}
+		if (target.type !== 'CallExpression' || !target.callee) return false;
+		const callee = unwrapChain(target.callee);
+		return (
+			callee.type === 'MemberExpression' &&
+			((memberName(callee) === 'get' && targetsRepositoryClass(target.arguments?.[0])) ||
+				(memberName(callee) === 'getRepository' && targetsEntity(target.arguments?.[0])))
+		);
+	};
+
+	const hasPolicedKey = (node: SyntaxNode) =>
+		node.type === 'ObjectExpression' &&
+		(node.properties ?? []).some((property) => {
+			if (property.type === 'SpreadElement' || !property.key) return false;
+			if (!property.computed && property.key.type === 'Identifier') {
+				return property.key.name === policedKey;
+			}
+			return property.key.type === 'Literal' && property.key.value === policedKey;
+		});
+
+	const isEntityQueryBuilder = (node: SyntaxNode): boolean => {
+		const call = unwrapChain(node);
+		if (call.type !== 'CallExpression' || !call.callee) return false;
+		const callee = unwrapChain(call.callee);
+		if (callee.type !== 'MemberExpression' || !callee.object) return false;
+		const method = memberName(callee);
+		if (method === 'createQueryBuilder') return isRepository(callee.object);
+		if (method !== 'update') return false;
+		return (
+			targetsEntity(call.arguments?.[0]) ||
+			(call.arguments?.length === 0 && isEntityQueryBuilder(callee.object))
+		);
+	};
+
+	const entityTypeArgument = new RegExp(`<[^>]*\\b${entityName}\\b[^>]*>`);
+	const updateTypeArgument = new RegExp(`update\\s*<[^>]*\\b${entityName}\\b[^>]*>`);
+
+	return ESLintUtils.RuleCreator.withoutDocs({
+		meta: {
+			type: 'problem',
+			docs: { description },
+			messages: { unsealedWrite: message },
+			schema: [],
+		},
+		defaultOptions: [],
+		create(context) {
+			if (
+				NON_RUNTIME_FILE.test(context.filename) ||
+				DATABASE_MIGRATION_FILE.test(context.filename) ||
+				repositoryFile.test(context.filename)
+			) {
+				return {};
+			}
+
+			return {
+				CallExpression(node) {
+					const callee = unwrapChain(node.callee as never);
+					if (callee.type !== 'MemberExpression' || !callee.object) return;
+					const method = memberName(callee);
+					if (!method) return;
+
+					if (WRITE_METHODS.has(method) && isRepository(callee.object)) {
+						context.report({ node, messageId: 'unsealedWrite' });
+						return;
+					}
+
+					const secondArgument = node.arguments[1];
+					if (
+						method === 'update' &&
+						isRepository(callee.object) &&
+						secondArgument !== undefined &&
+						secondArgument.type !== 'SpreadElement' &&
+						hasPolicedKey(secondArgument as never)
+					) {
+						context.report({ node, messageId: 'unsealedWrite' });
+						return;
+					}
+
+					// Only the text between the callee and its arguments is the type argument list.
+					// Cutting the whole call at the first `(` stops inside a receiver such as
+					// `container.get(dataSource)`, which hides the type argument.
+					const callText = context.sourceCode.getText(node);
+					const calleeText = context.sourceCode.getText(callee as never);
+					const afterCallee = callText.startsWith(calleeText)
+						? callText.slice(calleeText.length)
+						: callText;
+					const hasEntityTypeArgument = entityTypeArgument.test(afterCallee.split('(', 1)[0]);
+					const explicitEntityTarget = targetsEntity(node.arguments[0] as never);
+					const updatePayload = explicitEntityTarget ? node.arguments[2] : node.arguments[1];
+					if (
+						method === 'update' &&
+						(explicitEntityTarget || hasEntityTypeArgument) &&
+						updatePayload !== undefined &&
+						updatePayload.type !== 'SpreadElement' &&
+						hasPolicedKey(updatePayload as never)
+					) {
+						context.report({ node, messageId: 'unsealedWrite' });
+						return;
+					}
+
+					const queryBuilderText = callee.object
+						? context.sourceCode.getText(callee.object as never)
+						: '';
+					if (
+						method === 'set' &&
+						node.arguments[0]?.type !== 'SpreadElement' &&
+						hasPolicedKey(node.arguments[0] as never) &&
+						(isEntityQueryBuilder(callee.object) || updateTypeArgument.test(queryBuilderText))
+					) {
+						context.report({ node, messageId: 'unsealedWrite' });
+						return;
+					}
+
+					if (
+						WRITE_METHODS.has(method) &&
+						node.arguments[0]?.type !== 'SpreadElement' &&
+						targetsEntity(node.arguments[0] as never)
+					) {
+						context.report({ node, messageId: 'unsealedWrite' });
+						return;
+					}
+
+					if (
+						method === 'into' &&
+						node.arguments[0]?.type !== 'SpreadElement' &&
+						targetsEntity(node.arguments[0] as never)
+					) {
+						context.report({ node, messageId: 'unsealedWrite' });
+						return;
+					}
+
+					for (const argument of node.arguments) {
+						if (
+							argument.type === 'Literal' &&
+							typeof argument.value === 'string' &&
+							rawWrite.test(argument.value)
+						) {
+							context.report({ node: argument, messageId: 'unsealedWrite' });
+						}
+						if (
+							argument.type === 'TemplateLiteral' &&
+							rawWrite.test(
+								argument.quasis.map((quasi) => quasi.value.cooked ?? quasi.value.raw).join(''),
+							)
+						) {
+							context.report({ node: argument, messageId: 'unsealedWrite' });
+						}
+					}
+				},
+			};
+		},
+	});
+};
diff --git a/packages/@n8n/oxlint-config/src/configs/base.ts b/packages/@n8n/oxlint-config/src/configs/base.ts
index c4bb482b5d3..87d45f17ae3 100644
--- a/packages/@n8n/oxlint-config/src/configs/base.ts
+++ b/packages/@n8n/oxlint-config/src/configs/base.ts
@@ -224,6 +224,7 @@ export const baseConfig = defineConfig({
 		'n8n-local-rules/no-restricted-sleep-definition': 'error',
 		'n8n-local-rules/no-restricted-sleep-import': 'error',
 		'n8n-local-rules/no-type-only-import-in-di': 'error',
+		'n8n-local-rules/no-unsealed-credentials-entity-write': 'error',
 		'n8n-local-rules/no-unsealed-workflow-entity-write': 'error',
 		'n8n-local-rules/no-unneeded-backticks': 'error',
 		'n8n-local-rules/no-unused-param-in-catch-clause': 'error',
diff --git a/packages/cli/eslint.config.mjs b/packages/cli/eslint.config.mjs
index 67c57a45f19..fba891470fa 100644
--- a/packages/cli/eslint.config.mjs
+++ b/packages/cli/eslint.config.mjs
@@ -67,6 +67,10 @@ export default defineConfig(
 							rule: 'no-unsealed-workflow-entity-write',
 							message: 'Route the write through a token-gated `WorkflowRepository` method.',
 						},
+						{
+							rule: 'no-unsealed-credentials-entity-write',
+							message: 'Route the write through a token-gated `CredentialsRepository` method.',
+						},
 					],
 				},
 			],
diff --git a/packages/cli/oxlint.config.mts b/packages/cli/oxlint.config.mts
index eaba2e4b5b5..434380ca284 100644
--- a/packages/cli/oxlint.config.mts
+++ b/packages/cli/oxlint.config.mts
@@ -66,6 +66,10 @@ export default defineConfig({
 						rule: 'no-unsealed-workflow-entity-write',
 						message: 'Route the write through a token-gated `WorkflowRepository` method.',
 					},
+					{
+						rule: 'no-unsealed-credentials-entity-write',
+						message: 'Route the write through a token-gated `CredentialsRepository` method.',
+					},
 				],
 			},
 		],
@@ -103,6 +107,17 @@ export default defineConfig({
 		'typescript/no-duplicate-type-constituents': 'warn',
 	},
 	overrides: [
+		{
+			// Shrink-only ratchet: the two import paths that upsert a whole credential row,
+			// including `type`. There is no sealed credential import method yet.
+			// NEVER add to this list — the override is per file, so a second write here
+			// goes unreported.
+			files: [
+				'./src/commands/import/credentials.ts',
+				'./src/modules/source-control.ee/source-control-import.service.ee.ts',
+			],
+			rules: { 'n8n-local-rules/no-unsealed-credentials-entity-write': 'off' },
+		},
 		{
 			// Public API guardrail: handlers/controllers must go through a service, never a repository.
 			files: ['./src/public-api/v1/handlers/**/*.ts', './src/public-api/v1/controllers/**/*.ts'],
diff --git a/packages/cli/src/__tests__/credentials-helper.test.ts b/packages/cli/src/__tests__/credentials-helper.test.ts
index 563df922186..46da2ed569c 100644
--- a/packages/cli/src/__tests__/credentials-helper.test.ts
+++ b/packages/cli/src/__tests__/credentials-helper.test.ts
@@ -1047,13 +1047,10 @@ describe('CredentialsHelper', () => {
 
 			expect(credentialsRepository.update).toHaveBeenCalledWith(
 				{ id: 'cred-123', type: 'oAuth2Api' },
-				expect.objectContaining({
-					id: 'cred-123',
-					name: 'Test OAuth2 Credential',
-					type: 'oAuth2Api',
+				{
 					data: expect.any(String),
 					updatedAt: expect.any(Date),
-				}),
+				},
 			);
 
 			const updateCall = credentialsRepository.update.mock.calls[0];
@@ -1277,11 +1274,10 @@ describe('CredentialsHelper', () => {
 				expect(storeOAuthTokenDataSpy).not.toHaveBeenCalled();
 				expect(credentialsRepository.update).toHaveBeenCalledWith(
 					{ id: 'cred-789', type: 'oAuth2Api' },
-					expect.objectContaining({
-						id: 'cred-789',
+					{
 						data: expect.any(String),
 						updatedAt: expect.any(Date),
-					}),
+					},
 				);
 
 				// Verify OAuth token was updated in database
@@ -1324,11 +1320,10 @@ describe('CredentialsHelper', () => {
 				expect(storeOAuthTokenDataSpy).not.toHaveBeenCalled();
 				expect(credentialsRepository.update).toHaveBeenCalledWith(
 					{ id: 'cred-789', type: 'oAuth2Api' },
-					expect.objectContaining({
-						id: 'cred-789',
+					{
 						data: expect.any(String),
 						updatedAt: expect.any(Date),
-					}),
+					},
 				);
 
 				// Verify OAuth token was updated in database
diff --git a/packages/cli/src/credentials-helper.ts b/packages/cli/src/credentials-helper.ts
index c89e4b34176..b673a0753e5 100644
--- a/packages/cli/src/credentials-helper.ts
+++ b/packages/cli/src/credentials-helper.ts
@@ -808,10 +808,12 @@ export class CredentialsHelper extends ICredentialsHelper {
 		const credentials = await this.getCredentials(nodeCredentials, type);
 
 		await credentials.setData(data);
-		const newCredentialsData = credentials.getDataToSave() as ICredentialsDb;
-
-		// Add special database related data
-		newCredentialsData.updatedAt = new Date();
+		// Ciphertext only. `name` and `type` would be written back unchanged, and a payload
+		// that cannot carry `type` keeps this off the sealed `credentialSave` path.
+		const newCredentialsData: Pick<ICredentialsDb, 'data' | 'updatedAt'> = {
+			data: credentials.getDataToSave().data,
+			updatedAt: new Date(),
+		};
 
 		// Save the credentials in DB
 		const findQuery = {
@@ -865,10 +867,12 @@ export class CredentialsHelper extends ICredentialsHelper {
 		const credentials = await this.getCredentials(nodeCredentials, type);
 
 		await credentials.updateData({ oauthTokenData: data.oauthTokenData });
-		const newCredentialsData = credentials.getDataToSave() as ICredentialsDb;
-
-		// Add special database related data
-		newCredentialsData.updatedAt = new Date();
+		// Ciphertext only. `name` and `type` would be written back unchanged, and a payload
+		// that cannot carry `type` keeps this off the sealed `credentialSave` path.
+		const newCredentialsData: Pick<ICredentialsDb, 'data' | 'updatedAt'> = {
+			data: credentials.getDataToSave().data,
+			updatedAt: new Date(),
+		};
 
 		// Save the credentials in DB
 		const findQuery = {
diff --git a/packages/cli/src/oauth/__tests__/oauth.service.test.ts b/packages/cli/src/oauth/__tests__/oauth.service.test.ts
index 5420b1c751b..89feea5b77c 100644
--- a/packages/cli/src/oauth/__tests__/oauth.service.test.ts
+++ b/packages/cli/src/oauth/__tests__/oauth.service.test.ts
@@ -451,9 +451,6 @@ describe('OauthService', () => {
 			await service.encryptAndSaveData(credential, toUpdate, toDelete);
 
 			expect(credentialsRepository.update).toHaveBeenCalledWith('1', {
-				id: '1',
-				name: expect.anything(),
-				type: 'test',
 				data: expect.any(String),
 				updatedAt: expect.any(Date),
 			});
@@ -472,9 +469,6 @@ describe('OauthService', () => {
 			await service.encryptAndSaveData(credential, toUpdate);
 
 			expect(credentialsRepository.update).toHaveBeenCalledWith('1', {
-				id: '1',
-				name: expect.anything(),
-				type: 'test',
 				data: expect.any(String),
 				updatedAt: expect.any(Date),
 			});
diff --git a/packages/cli/src/oauth/oauth.service.ts b/packages/cli/src/oauth/oauth.service.ts
index cd0ff3d2692..bf23692438d 100644
--- a/packages/cli/src/oauth/oauth.service.ts
+++ b/packages/cli/src/oauth/oauth.service.ts
@@ -415,10 +415,13 @@ export class OauthService {
 
 		const credentials = new Credentials(credential, credential.type, credential.data);
 		await credentials.updateData(toUpdate, toDelete);
-		await this.credentialsRepository.update(credential.id, {
-			...credentials.getDataToSave(),
+		// Ciphertext only. `name` and `type` would be written back unchanged, and a payload
+		// that cannot carry `type` keeps this off the sealed `credentialSave` path.
+		const update: Pick<ICredentialsDb, 'data' | 'updatedAt'> = {
+			data: credentials.getDataToSave().data,
 			updatedAt: new Date(),
-		});
+		};
+		await this.credentialsRepository.update(credential.id, update);
 	}
 
 	/** Get a credential without user check */