# CVE-2026-125321: pgEdge Postgres MCP Server login rate limiting can be evaded by a caller-supplied header


- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 10 Nov 2026
- **Updated:** 10 Nov 2026
- **Also known as:** GHSA-v347-v3w7-7fq9

## 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.

Weakness: CWE-807 (Reliance on Untrusted Inputs in a Security Decision), CWE-770 (Allocation of Resources Without Limits or Throttling)

## 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-125321 and fix it if it is affected.

What it is: CVE-2026-125321 is a medium-severity vulnerability in pgedge-postgres-mcp, published on 10 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-125321 in the wild and no public exploit code.

Affected product: pgedge-postgres-mcp. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-125321/ (Markdown: https://insights.sbomify.com/CVE-2026-125321/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-125321
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-125321
- OSV: https://osv.dev/vulnerability/CVE-2026-125321

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-125321/
Summaries are generated and may contain mistakes; the official description above is the record.