CVE-2025-66220
5.0 · MEDIUMOverview
CVE-2025-66220 is a medium-severity vulnerability affecting envoyproxy envoy. It was published on December 3, 2025 and has a CVSS 3.1 base score of 5.0 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.0, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from envoyproxy. Update envoy to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| envoyproxy | envoy | >= 0, < 1.33.13 | Affected |
Frequently Asked Questions
What is CVE-2025-66220?
CVE-2025-66220 is a medium-severity vulnerability affecting envoyproxy envoy. It was published on December 3, 2025 and has a CVSS 3.1 base score of 5.0 (MEDIUM).
How severe is CVE-2025-66220?
This vulnerability has a CVSS 3.1 base score of 5.0, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2025-66220?
Check the references section for vendor advisories and patches from envoyproxy. Update envoy to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-66220?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-66220 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
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