CVSS 4.0
9.1 criticalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NCVE-2026-88007
Critical (9.1) in traefik traefik. EPSS 0.6% chance of exploitation in the next 30 days. Fixed in github.com/traefik/traefik/v3 3.7.13.
Traefik 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 service.AddTransportOnContext, so kerberosRoundTripper uses a shared backend transport instead of a transport dedicated to each frontend connection. With HTTP/3 enabled, a backend using connection-bound NTLM or Negotiate authentication, and backend keep-alive, an unrelated client can reuse a backend connection authenticated for a victim, read victim-only data, and act as that victim without the victim credentials. This issue is fixed in 2.11.57 and 3.7.13.
Severity
CVSS 3.1
9.1 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N- EPSS
- 0.6% chance of exploitation in the next 30 days; higher than 48% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-287, CWE-863
- Published
- Modified
- Record from
- the NVD, synced
Affected
- traefik:traefik
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-qqjf-53cj-pwvv | Go | github.com/traefik/traefik/v3 | >=3.0.0 <3.7.13 | 3.7.13 |
| GHSA-qqjf-53cj-pwvv | Go | github.com/traefik/traefik/v2 | >=2.11.0 <2.11.57 | 2.11.57 |
| GO-2026-6466 | Go | github.com/traefik/traefik | all versions | no fix published |
| GO-2026-6466 | Go | github.com/traefik/traefik/v2 | >=2.11.0 <2.11.57 | 2.11.57 |
| GO-2026-6466 | Go | github.com/traefik/traefik/v3 | >=3.0.0 <3.7.13 | 3.7.13 |
References
- https://github.com/traefik/traefik/commit/ff39c47d7459dec9cd8de63c1a4e7aa7315bdc1c
- https://github.com/traefik/traefik/pull/13812
- https://github.com/traefik/traefik/releases/tag/v2.11.57
- https://github.com/traefik/traefik/releases/tag/v3.7.13
- https://github.com/traefik/traefik/security/advisories/GHSA-qqjf-53cj-pwvv