CVE-2026-71324

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

1.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-08-06 22:18 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-16 20:46 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.1% in the next 30 days (EPSS).
• Severity: 7.0 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-08-06 22:18 UTC

Last modified

2026-09-16 20:46 UTC

Exploit probability

1.1% · EPSS, next 30 days

Weakness

CWE-444

Record status

Analyzed

Affected

• Traefik < 2.11.53
• Traefik < 3.6.24
• Traefik < 3.7.9

Attack profile CVSS 4.0 · 7.0

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

None

Confidentiality

None

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-71324.md and follow it. Check whether this project is affected by CVE-2026-71324. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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