CVE-2025-66220 — MEDIUM (5.0)

Q: How severe is CVE-2025-66220?

CVE-2025-66220 has been rated MEDIUM with a CVSS base score of 5.0/10. Review the CVSS metrics above for detailed severity breakdown.

Q: Is there a patch for CVE-2025-66220?

Check the references section above for vendor advisories and patch information. Affected products include: Envoyproxy Envoy.

Vulnerability Description

Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, Envoy’s mTLS certificate matcher for match_typed_subject_alt_names may incorrectly treat certificates containing an embedded null byte (\0) inside an OTHERNAME SAN value as valid matches.

CVSS Score

5.0

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:L/A:N

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

LOW

Availability

NONE

Affected Products

Vendor	Product	Versions
Envoyproxy	Envoy	< 1.33.13

Related Weaknesses (CWE)

CWE-170

References

https://github.com/envoyproxy/envoy/security/advisories/GHSA-rwjg-c3h2-f57pExploitVendor Advisory

FAQ

What is CVE-2025-66220?

CVE-2025-66220 is a vulnerability with a CVSS score of 5.0 (MEDIUM). Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, Envoy’s mTLS certificate matcher for match_typed_subject_alt_names may incorrectly treat certif...

How severe is CVE-2025-66220?

CVE-2025-66220 has been rated MEDIUM with a CVSS base score of 5.0/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2025-66220?

Check the references section above for vendor advisories and patch information. Affected products include: Envoyproxy Envoy.