Traefik 2.11.0 before 2.11.58 and 3.0.0 before 3.7.14 stores its NTLM/Kerberos backend round tripper in a client-connection slot not keyed by ServersTransport, so one service's TLS client configuration is reused for another service's backend. An unauthenticated client can arm the slot via a backend issuing an NTLM or Negotiate challenge, then reach another service on the same keep-alive connection, bypassing its root CAs, server name, and certificate verification.
Fix
Patch, vendor advisory and mitigation references on NVD 1
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 10
- Cpes+1 CPE criteria (now 1)NVD modified 2026-10-27 14:13
- StatusPublished → AnalyzedNVD modified 2026-10-27 14:13
- StatusUndergoing Analysis → PublishedNVD modified 2026-10-23 15:07
- StatusPublished → Undergoing AnalysisNVD modified 2026-10-23 15:17
- StatusUndergoing Analysis → PublishedNVD modified 2026-10-22 01:43
- StatusPublished → Undergoing AnalysisNVD modified 2026-10-22 15:39
- StatusReceived → PublishedNVD modified 2026-10-22 01:43
- StatusPublished → ReceivedNVD modified 2026-10-22 02:16
- CVSS7.0 (v4.0, CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N) → 7.0 (v4.0, CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X)NVD modified 2026-10-22 02:16
- First seenCVSS 7.0 · traefikNVD modified 2026-10-22 01:43
Affected (CPE criteria) 1
cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*