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CVE-2025-66491 Detail

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.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/traefik/traefik/commit/14a1aedf5704673d875d210d7bacf103a43c77e4 GitHub, Inc.
https://github.com/traefik/traefik/releases/tag/v3.6.3 GitHub, Inc.
https://github.com/traefik/traefik/security/advisories/GHSA-7vww-mvcr-x6vj GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-295 Improper Certificate Validation GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-66491
NVD Published Date:
12/08/2025
NVD Last Modified:
12/09/2025
Source:
GitHub, Inc.