Description
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.
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Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-3ccp-42pg-hgv6 | Traefik: Cross-user response poisoning via proxied CONNECT on Traefik's shared backend keep-alive pool |
References
History
Fri, 07 Aug 2026 02:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Traefik
Traefik traefik |
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| Vendors & Products |
Traefik
Traefik traefik |
Thu, 06 Aug 2026 22:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Traefik: Cross-user response poisoning via proxied CONNECT on Traefik's shared backend keep-alive pool | |
| Weaknesses | CWE-444 | |
| References |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-08-06T15:56:33.112Z
Reserved: 2026-08-05T18:14:42.065Z
Link: CVE-2026-71324
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OpenCVE Enrichment
Updated: 2026-08-07T02:00:06Z
Weaknesses
Github GHSA