Skip to content
OpenAdvisories
High · 7.0 Public exploit CVE-2026-88008 EUVD-2026-75545GHSA-w4v4-9rw7-5326GO-2026-6468

Traefik: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') and Incorrect Authorization

Published Sep 10, 2026 · Updated Sep 10, 2026 · Assigned by GitHub_M

Vendor: traefik Product: traefik Package: github.com/traefik/traefik Package: github.com/traefik/traefik/v2 Package: github.com/traefik/traefik/v3 Package: traefik-3.6 Ecosystem: Go Ecosystem: Wolfi

Description

Traefik is an open source HTTP reverse proxy and load balancer. From 2.11.26 until 2.11.57 and 3.7.13, Traefik forwards a client-supplied Connection header requesting Upgrade, the Upgrade: h2c token, and HTTP2-Settings to a shared backend. If the backend accepts h2c and returns 101 Switching Protocols, Traefik enters a raw tunnel and no longer applies routers, BasicAuth, ForwardAuth, IPAllowList, RateLimit, access logging, metrics, or tracing to later HTTP/2 requests, allowing an unauthenticated request through an unprotected route to reach protected paths on the same backend. This issue is fixed in 2.11.57 and 3.7.13.

Affected products

VendorProductAffectedFixed
traefik traefik >= 2.11.26, < 2.11.57, >= 3.4.2, < 3.7.13 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

SUSE

Security tracker ↗
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 govulncheck-vulndb 0.0.20260916T180043-160000.1.1 SUSE-SU-2026:23863-1, SUSE-SU-2026:23855-1
SLES 16.0 govulncheck-vulndb 0.0.20260916T180043-160000.1.1 SUSE-SU-2026:23863-1, SUSE-SU-2026:23855-1

openSUSE

Security tracker ↗
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed traefik 3.7.13-1.1 openSUSE-SU-2026:12076-1
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260916T180043-160000.1.1 openSUSE-SU-2026:21897-1

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling traefik-3.6 No fix yet —

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

  • Boreas37/CVE-2026-88008-PoC ★ 0 · Sep 27, 2026

    CVE-2026-88008 - Traefik (<=2.11.56 / <=3.7.12): a client-controlled h2c upgrade tunnels past routers and middleware (BasicAuth/ForwardAuth/IPAllowList), unauthorised access + no access logging. Stdl…

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/traefik/traefik all versions — GO-2026-6468
Go github.com/traefik/traefik/v2 >= 2.11.26, < 2.11.57 2.11.57 GHSA-w4v4-9rw7-5326
Go github.com/traefik/traefik/v3 >= 3.4.2, < 3.7.13 3.7.13 GHSA-w4v4-9rw7-5326

Advisories 4

References