Description
Traefik 2.11.x before 2.11.58 and 3.x before 3.7.14 contains a race condition in NTLM and Kerberos (Negotiate) backend authentication, where the per-connection sticky round tripper slot is read and written without synchronization. Remote attackers can send concurrent HTTP/2 or HTTP/3 requests over one connection to orphan backend connections, break connection-bound authentication, or crash Traefik.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| traefik | traefik | 2.11.0 – < 2.11.58, 3.0.0 – < 3.7.14 | 2.11.58 |
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.
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | traefik | 3.7.16-1.1 | openSUSE-SU-2026:12281-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | traefik-3.6 | No fix yet | — |
Advisories 1
- openSUSE-SU-2026:12281-1 traefik-3.7.16-1.1 on GA media SUSE / openSUSE Security Updates · Oct 27, 2026
References
- GitHub Security Advisory (GHSA-mhjw-hmjv-p99x) vendor-advisory
- VulnCheck Advisory: Traefik before 2.11.58 and 3.7.14 Race Condition in NTLM/Kerberos Round Tripper third-party-advisory