CVE Vulnerabilities

CVE-2025-66220

Improper Null Termination

Published: Dec 03, 2025 | Modified: Dec 05, 2025
CVSS 3.x
7.1
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu

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.

Weakness

The product does not terminate or incorrectly terminates a string or array with a null character or equivalent terminator.

Affected Software

Name Vendor Start Version End Version
Envoy Envoyproxy * 1.33.13 (excluding)
Envoy Envoyproxy 1.34.0 (including) 1.34.11 (excluding)
Envoy Envoyproxy 1.35.0 (including) 1.35.7 (excluding)
Envoy Envoyproxy 1.36.0 (including) 1.36.3 (excluding)

Potential Mitigations

References