CVEvulnerability

CVE-2026-88004

7.0 HIGH Published 2026-09-10 Modified 2026-09-14 Official page ↗
Status
Analyzed
Published
2026-09-10
Last modified
2026-09-14
Assigner
[email protected]
CVSS 4.0 ([email protected])
7.0 HIGH — CVSS:4.0/AV:N/AC:H/AT:N/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:X/V:X/RE:X/U:X
CVSS 3.1 ([email protected])
7.4 HIGH — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Weaknesses
CWE-436, CWE-807

Description

Traefik is an open source HTTP reverse proxy and load balancer. From 3.2.0 until 3.7.13, Traefik entrypoint defenses aliasHeadersStrategy, underscoreHeadersStrategy, and forwardedHeaders inspect req.Header but not req.Trailer, allowing an unauthenticated client to submit an aliasing or trusted header name in an HTTP/1.1 chunked trailer or an HTTP/2 trailer. When the retry or buffering middleware reads the body before the reverse proxy clones the request, the attacker-controlled trailer value reaches a backend that merges trailers into the header namespace, bypassing the documented delete or reject behavior and potentially spoofing identity or forwarded routing data. This issue is fixed in 3.7.13.

Affected configurations

• traefik traefik (>= 3.2.0 < 3.7.13)

Related

Weakness · CWE (2)

  • CWE-436 Interpretation Conflict weakness
  • CWE-807 Reliance on Untrusted Inputs in a Security Decision weakness

References