← Vulnerability feed

Vulnerability record · CVE-2026-71324 · published 6 August 2026

CVE-2026-71324: Traefik http request smuggling vulnerability

Traefik · Traefik

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.

7.0 CVSS 4.0 High EPSS 0.69% · top 49.0% CWE-444 · HTTP request smuggling
7.0CVSS 4.0 base score
0.69%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
10References
16 Sep 2026Last modified by NVD

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.

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
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 TrackingPatch
https://github.com/traefik/traefik/pull/13543 Issue TrackingPatch
https://github.com/traefik/traefik/pull/13556 Issue TrackingPatch
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 PatchVendor Advisory

Track CVE-2026-71324 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

7.5CVE-2023-44487HTTP/2 Rapid Reset stream cancellation denial of serviceThe HTTP/2 protocol permits a client to cancel many streams quickly, and the server's handling of those resets consumes disproportionate resources. T…KEVEPSS 100%analysed9.3CVE-2026-88877Traefik insecure direct object reference vulnerabilityTraefik is a HTTP reverse proxy and load balancer. In versions >= v3.7.0 and <= v3.7.11, the Kubernetes ingress-nginx provider mishandles Ingresses t…EPSS 0.65%9.3CVE-2026-85595Traefik improper authentication vulnerabilityTraefik versions before v2.11.55 and versions v3.0.0 through v3.7.10 contain an authentication bypass vulnerability in the digestAuth middleware wher…EPSS 0.69%9.1CVE-2026-88007Traefik improper authentication vulnerabilityTraefik is an open source HTTP reverse proxy and load balancer. From 2.11.0 until 2.11.57 and 3.7.13, the HTTP/3 entrypoint ConnContext does not call…EPSS 0.60%8.8CVE-2026-88009Traefik http request smuggling vulnerabilityTraefik is an open source HTTP reverse proxy and load balancer. Prior to 2.11.57, and 3.7.13, Traefik accepts a rootless HTTP/1 request target that G…EPSS 0.44%8.8CVE-2025-32431Traefik path traversal vulnerabilityTraefik (pronounced traffic) is an HTTP reverse proxy and load balancer. In versions prior to 2.11.24, 3.3.6, and 3.4.0-rc2. There is a potential vul…EPSS 0.93%8.7CVE-2023-54365Traefik uncontrolled resource consumption vulnerabilityTraefik before 2.10.5 and 3.0.0-beta4 is affected by a denial-of-service vulnerability in HTTP/2 request handling inherited from the Go standard libr…EPSS 0.77%8.2CVE-2026-85596Traefik improper authentication vulnerabilityTraefik versions >= v3.7.0 and <= v3.7.10 contain an authentication bypass in the Kubernetes Ingress NGINX provider. The TLS option generated for an …EPSS 0.43%

Source: NIST National Vulnerability Database (record CVE-2026-71324), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.