critical9.1
CVE-2026-88007
Traefik is an open source HTTP reverse proxy and load balancer.
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/traefik/traefik/v3 | >= 3.0.0, < 3.7.13 | 3.7.13 |
| go | github.com/traefik/traefik/v2 | >= 2.11.0, < 2.11.57 | 2.11.57 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Traefik | Traefik | from 2.8.2 before 2.11.56 from 3.0.0 before 3.7.12 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-qqjf-53cj-pwvv
- https://github.com/traefik/traefik/security/advisories/GHSA-qqjf-53cj-pwvv
- https://nvd.nist.gov/vuln/detail/CVE-2026-88007
- https://github.com/traefik/traefik/pull/13812
- https://github.com/traefik/traefik/commit/ff39c47d7459dec9cd8de63c1a4e7aa7315bdc1c
- https://github.com/traefik/traefik/releases/tag/v2.11.57
- https://github.com/traefik/traefik/releases/tag/v3.7.13