Traefik is an open source HTTP reverse proxy and load balancer. Prior to 2.11.53, 3.6.24, and 3.7.9, Traefik's default HTTP reverse proxy forwards a plain HTTP/2 or HTTP/3 CONNECT request and its body to an HTTP/1.1 upstream through a shared net/http.Transport. When the upstream answers the CONNECT with a keep-alive non-2xx response and does not drain the body, Traefik returns the desynchronized backend socket to its shared pool and reuses it for other clients. An unauthenticated attacker can use this behavior to make a different client read the attacker's smuggled response, which can include authenticated or private content from another request. The ForwardAuth middleware with forwardBody true and preserveRequestMethod true can re-issue a CONNECT with the buffered body attached, exposing the auth-client pool to the same desynchronization. This issue is fixed in 2.11.53, 3.6.24, and 3.7.9.
References
| Link | Resource |
|---|---|
| https://github.com/traefik/traefik/commit/04d36f28e4eae7535e96a6351dd9f7bfb48a30e7 | Patch |
| https://github.com/traefik/traefik/commit/0807b6d5dd1da8b2f7f4076ea2392b5437bf2ab0 | Patch |
| https://github.com/traefik/traefik/commit/94a7508817d180f0ab2f1eae93df48d4ab19ecce | Patch |
| https://github.com/traefik/traefik/pull/13542 | Issue Tracking Patch |
| https://github.com/traefik/traefik/pull/13543 | Issue Tracking Patch |
| https://github.com/traefik/traefik/pull/13556 | Issue Tracking Patch |
| https://github.com/traefik/traefik/releases/tag/v2.11.53 | Release Notes |
| https://github.com/traefik/traefik/releases/tag/v3.6.24 | Release Notes |
| https://github.com/traefik/traefik/releases/tag/v3.7.9 | Release Notes |
| https://github.com/traefik/traefik/security/advisories/GHSA-3ccp-42pg-hgv6 | Patch Vendor Advisory |
Configurations
Configuration 1 (hide)
|
History
16 Sep 2026, 20:46
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Traefik
Traefik traefik |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 9.1 |
| CPE | cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:* | |
| References | () https://github.com/traefik/traefik/commit/04d36f28e4eae7535e96a6351dd9f7bfb48a30e7 - Patch | |
| References | () https://github.com/traefik/traefik/commit/0807b6d5dd1da8b2f7f4076ea2392b5437bf2ab0 - Patch | |
| References | () https://github.com/traefik/traefik/commit/94a7508817d180f0ab2f1eae93df48d4ab19ecce - Patch | |
| References | () https://github.com/traefik/traefik/pull/13542 - Issue Tracking, Patch | |
| References | () https://github.com/traefik/traefik/pull/13543 - Issue Tracking, Patch | |
| References | () https://github.com/traefik/traefik/pull/13556 - Issue Tracking, Patch | |
| References | () https://github.com/traefik/traefik/releases/tag/v2.11.53 - Release Notes | |
| References | () https://github.com/traefik/traefik/releases/tag/v3.6.24 - Release Notes | |
| References | () https://github.com/traefik/traefik/releases/tag/v3.7.9 - Release Notes | |
| References | () https://github.com/traefik/traefik/security/advisories/GHSA-3ccp-42pg-hgv6 - Patch, Vendor Advisory |
Information
Published : 2026-08-06 22:18
Updated : 2026-09-16 20:46
NVD link : CVE-2026-71324
Mitre link : CVE-2026-71324
CVE.ORG link : CVE-2026-71324
JSON object : View
Products Affected
traefik
- traefik
CWE
CWE-444
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
