CVE-2025-66491

{"id": "CVE-2025-66491", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.9, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 3.6, "exploitabilityScore": 2.2}]}, "published": "2025-12-09T01:16:55.720", "references": [{"url": "https://github.com/traefik/traefik/commit/14a1aedf5704673d875d210d7bacf103a43c77e4", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/traefik/traefik/releases/tag/v3.6.3", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/traefik/traefik/security/advisories/GHSA-7vww-mvcr-x6vj", "tags": ["Patch", "Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-295"}]}], "descriptions": [{"lang": "en", "value": "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."}], "lastModified": "2026-01-02T21:12:07.183", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C2211A70-8944-46AA-B318-B3669174DBCE", "versionEndExcluding": "3.6.3", "versionStartIncluding": "3.5.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}