CVE-2026-125321 pgEdge Postgres MCP Server login rate limiting can be evaded by a caller-supplied header
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-125321?
CVE-2026-125321 is a medium-severity vulnerability in pgedge-postgres-mcp, published on 10 Nov 2026.
Official description
pgEdge Postgres MCP Server enables SQL queries against PostgreSQL databases through Model Context Protocol compatible clients. Prior to 1.1.0, deployments exposing the nondefault HTTP transport with authentication enabled used the leftmost caller-supplied X-Forwarded-For value as the client address for login rate limiting. ExtractIPAddress in internal/auth/middleware.go supplied that value to IsAllowed and RecordFailedAttempt in internal/auth/rate_limiter.go, allowing an unauthenticated caller to rotate addresses to evade throttling or assert another user's address to consume that user's limiter bucket. The published nginx configuration appended rather than replaced X-Forwarded-For, making the issue reachable without an operator misconfiguration. Username-keyed account lockout did not use the client address, but shipped defaults disabled that separate control through MaxFailedAttemptsBeforeLockout: 0. This issue is fixed in version 1.1.0.
Which versions are affected by CVE-2026-125321?
How do I fix CVE-2026-125321?
No fix has been published for CVE-2026-125321 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-125321 being exploited?
There is no known exploitation of CVE-2026-125321 in the wild and no public exploit code.
Sources
Also known as GHSA-v347-v3w7-7fq9.