CVE-2025-66491

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Source
https://cve.org/CVERecord?id=CVE-2025-66491
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-66491.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-66491
Aliases
Downstream
Published
2025-12-09T00:38:39.208Z
Modified
2026-03-01T02:54:56.892775Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N CVSS Calculator
Summary
Traefik has Inverted TLS Verification Logic in its ingress-nginx Provider
Details

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.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-295"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66491.json"
}
References

Affected packages

Git / github.com/traefik/traefik

Affected ranges

Type
GIT
Repo
https://github.com/traefik/traefik
Events
Introduced
2cbd96e64c929bea8f933efa75080e9656314f34
Fixed
8a621274b81cd177ea5f6e07a5d5472af7d213b3

Affected versions

v2.*
v2.11.29
v2.11.30
v2.11.31
v2.11.32
v3.*
v3.5.0
v3.5.1
v3.5.2
v3.5.3
v3.5.4
v3.5.6
v3.6.0
v3.6.0-rc1
v3.6.1
v3.6.2

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-66491.json"