Root cause
Authentication & access control introduced
The scope helper hashes complete credentials but returns an empty scope when either connection field is absent.
n8n-mcp could select the shared workflow-version storage scope when a multi-tenant request supplied incomplete connection details. The repair rejects incomplete tenant contexts before accessing version storage.
How AI contributed: Direct introductionPublished Jul 14, 2026 in 
czlonkowski/n8n-mcpAll 11 findings in this repository
Provisional finding. Full causal and release verification remains incomplete.
Fix
Security fix
The handler refuses multi-tenant requests that resolve to the empty storage scope.
Case facts
- CVE ID
- CVE-2026-55608
- GHSA ID
- GHSA-2CF7-HPWF-47H9
- Published
- Jul 14, 2026
- Severity
- medium
- Language
- TypeScript
- AI tool
Claude- AI role
- Direct introduction
- Vulnerable release
- <= 2.57.3
- Fixed release
- 2.57.4
AI-assisted change
AI-assisted changesrc/types/instance-context.tssource czlonkowski/n8n-mcp@ced57ab2ae+15−0
@@ -205,1 +217,16 @@+ * those deployments share a single logical tenant.+ *+ * Must be deterministic across processes and restarts: this id is persisted+ * in the database and compared on later reads/deletes. Do NOT use+ * createCacheKey() from cache-utils, which uses a per-process random salt.+ */+export function getInstanceScopeId(context?: InstanceContext): string {+ if (context?.n8nApiUrl && context?.n8nApiKey) {+ const url = context.n8nApiUrl.trim().replace(/\/+$/, '').toLowerCase();+ return createHash('sha256')Show 6 hidden lines
+ .update(`n8n-mcp-wv:${url}:${context.n8nApiKey}`)+ .digest('hex')+ .slice(0, 32);+ }+ return ''; }The scope helper hashes complete credentials but returns an empty scope when either connection field is absent.
Security fix
Fixsrc/mcp/handlers-n8n-manager.tssource czlonkowski/n8n-mcp@c1ca1e7369+10−0
@@ -2405,8 +2405,18 @@ ): Promise<McpToolResponse> { try { const input = workflowVersionsSchema.parse(args);++ // SECURITY (GHSA-2cf7-hpwf-47h9): multi-tenant requests must resolve a+ // complete tenant scope; fail closed otherwise.+ if (process.env.ENABLE_MULTI_TENANT === 'true' && getInstanceScopeId(context) === '') {+ return {+ success: false,+ error: 'Workflow version storage is not available for this tenant context'Show 8 hidden lines
+ };+ }+ const client = context ? getN8nApiClient(context) : null; const versioningService = new WorkflowVersioningService(repository, client || undefined, getInstanceScopeId(context)); switch (input.mode) { case 'list': {The handler refuses multi-tenant requests that resolve to the empty storage scope.
Patch fingerprints
AI-assisted change b448851a5827e4a9f1094601a505afa71529650c65b23ccbfb595d9e3bba195f · Fix 925bebe96a8ad6bc9fcb26d1796134ac38290583aea0a347ee054f1cc67ca9db