# CVE-2026-111934: Coder before 2.34.7 IP Spoofing via X-Forwarded-For Header

> Attackers can spoof IP addresses to bypass rate limits and falsify audit logs in Coder, enabling brute-force attacks.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** GHSA-vprw-xcrv-287h, GHSA-wxhj-4mx9-pqgf

## What is CVE-2026-111934?

CVE-2026-111934 is a medium-severity vulnerability in coder, published on 17 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Coder before 2.34.7 contains an IP spoofing vulnerability in the ExtractRealIPAddress middleware that trusts the leftmost, client-supplied X-Forwarded-For value instead of the client IP appended by a reverse proxy. Attackers can send forged X-Forwarded-For values through appending proxies to bypass per-IP rate limits on login, one-time passcode, and password validation endpoints, enabling brute-force attacks, and to falsify IP addresses recorded in audit logs.

Weakness: CWE-348 (Use of Less Trusted Source)

## Which versions are affected by CVE-2026-111934?


## How do I fix CVE-2026-111934?

No fix has been published for CVE-2026-111934 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-111934 being exploited?

There is no known exploitation of CVE-2026-111934 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-111934 and fix it if it is affected.

What it is: CVE-2026-111934 is a medium-severity vulnerability in coder, published on 17 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-111934 in the wild and no public exploit code.

Affected product: coder. 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-2026-111934/ (Markdown: https://insights.sbomify.com/CVE-2026-111934/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-111934
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111934
- OSV: https://osv.dev/vulnerability/CVE-2026-111934

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-111934/
Summaries are generated and may contain mistakes; the official description above is the record.