CVE-2025-66491
Traefik has Inverted TLS Verification Logic in its ingress-nginx Provider
- State
- Published
- Severity
- 5.9 Medium
- Published
- Dec 9, 2025
- Updated
- Dec 9, 2025
- Reserved
- Dec 2, 2025
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.9 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N | GitHub_M |
Weaknesses
- CWE-295 Improper Certificate Validation
Affected Products
| Product | Versions |
|---|---|
traefiktraefik |
|
References
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