CVE-2025-66220
Envoy’s TLS certificate matcher for `match_typed_subject_alt_names` may incorrectly treat certificates containing an embedded null byte
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.
INFO
Published Date :
Dec. 3, 2025, 7:15 p.m.
Last Modified :
Dec. 3, 2025, 7:15 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Envoy to a fixed version.
- Validate mTLS certificate configurations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-66220.
| URL | Resource |
|---|---|
| https://github.com/envoyproxy/envoy/security/advisories/GHSA-rwjg-c3h2-f57p |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-66220 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-66220
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-66220 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-66220 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Dec. 03, 2025
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:L/A:N Added CWE CWE-170 Added Reference https://github.com/envoyproxy/envoy/security/advisories/GHSA-rwjg-c3h2-f57p