CVE-2026-88007
Traefik HTTP/3 backend connection reuse across users - the HTTP/3 entrypoint's ConnContext never calls service.AddTransportOnContext, so a backend connection already authenticated by one client (NTLM/Negotiate, which authenticate the CONNECTION not the request) is handed to the next client and the backend answers as the first user (CVSS 9.1)
- Severity
- critical
- Affected product
- Traefik
- Affected versions
- Traefik ≥ 2.11.0, < 2.11.57
- Affected versions
- Traefik ≥ 3.0.0, < 3.7.13
- Fixed in
- Traefik 2.11.57
- Fixed in
- Traefik 3.7.13
- Detection basis
- Appliance fingerprint
- Shipped rule
- Traefik: Traefik HTTP/3 backend connection reuse across users - the HTTP/3 entrypoint's ConnContext never calls service.AddTransportOnContext, so a backend connection already authenticated by one client (NTLM/Negotiate, which authenticate the CONNECTION not the request) is handed to the next client and the backend answers as the first user (CVSS 9.1)
- Added to NewScan
- 2026-09-11
- Detected by
- NewScan — free, self-hosted
How NewScan reports it
APPLIANCE FINGERPRINT
NewScan fingerprints the Traefik appliance and reports this CVE when the detected version falls inside the affected range below.
APPLIANCE FINGERPRINT
NewScan fingerprints the Traefik appliance and reports this CVE when the detected version falls inside the affected range below.
References
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