Connect your agent
AdvisoriesCriticalCheck your lockfilePluginHow it worksPricing Connect your agent

Advisory record · GHSA-9cr8-q42q-g8m7

Traefik: HTTP/3 mTLS bypass via exact SNI TLSOptions lookup for wildcard and mixed-case hosts

CVSS 7.8 HighEPSS 0.0063 · 50th percentile

Published by the GitHub Advisory Database at 16 Jun 2026, 21:04 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
github.com/traefik/traefik/v3Go>=3.7.0, <3.7.3 || <3.6.183.7.3, 3.6.18
github.com/traefik/traefik/v2Go<2.11.512.11.51
github.com/traefik/traefikGo<=1.7.34No fixed version yet
Identifiers
GHSA-9cr8-q42q-g8m7 · CVE-2026-53622 · GO-2026-5287
Weakness (CWE)
CWE-288 · CWE-289
Tags
Published
16 Jun 2026
Updated
10 Sept 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Traefik v3 versions before 3.6.18 and from 3.7.0 before 3.7.3, Traefik v2 before 2.11.51, and Traefik v1 at or below 1.7.34 are affected, with fixes in 3.6.18, 3.7.3, and 2.11.51; no fix is listed for v1. When HTTP/3 is enabled, TLS option lookup is case-sensitive and exact, so a router's mTLS requirement can be skipped for wildcard or mixed-case hostnames. An unauthenticated client that can reach the UDP entrypoint may then reach a backend that requires client certificates. Upgrade to a fixed version, or disable HTTP/3 on affected entrypoints as a workaround.

Written 1 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
7.8 High 4.0 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0063, the 50th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:14 UTC First seen by agentprime
  2. 31 Oct 2026, 14:14 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.