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CVE-2025-66491

NVD

https://nvd.nist.gov/vuln/detail/CVE-2025-66491

Severity

5.9

Medium

CVSS V3

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Summary

Traefik has Inverted TLS Verification Logic in its ingress-nginx Provider

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.

References

Affected packages

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