CVEvulnerability

CVE-2025-66491

5.9 MEDIUM Published 2025-12-09 Modified 2026-10-14 Official page ↗
Status
Analyzed
Published
2025-12-09
Last modified
2026-10-14
Assigner
[email protected]
CVSS 3.1 ([email protected])
5.9 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Weaknesses
CWE-295

Description

Traefik is an HTTP reverse proxy and load balancer. Versions 3.5.0 through 3.6.2 have inverted TLS verification logic in the nginx.ingress.kubernetes.io/proxy-ssl-verify annotation. Setting the annotation to "on" (intending to enable backend TLS certificate verification) actually disables verification, allowing man-in-the-middle attacks against HTTPS backends when operators believe they are protected. This issue is fixed in version 3.6.3.

Affected configurations

• traefik traefik (>= 3.5.0 < 3.6.3)

Related

Weakness · CWE (1)

  • CWE-295 Improper Certificate Validation weakness

References