CVE-2025-66220
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-12-03

Last updated on: 2025-12-05

Assigner: GitHub, Inc.

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.
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Meta Information
Published
2025-12-03
Last Modified
2025-12-05
Generated
2026-06-16
AI Q&A
2025-12-03
EPSS Evaluated
2026-06-15
NVD
CVE-2025-66220
EUVD
EUVD-2025-201090
Affected Vendors & Products
Showing 4 associated CPEs
Vendor Product Version / Range
envoyproxy envoy to 1.33.13 (exc)
envoyproxy envoy From 1.34.0 (inc) to 1.34.11 (exc)
envoyproxy envoy From 1.35.0 (inc) to 1.35.7 (exc)
envoyproxy envoy From 1.36.0 (inc) to 1.36.3 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-170 The product does not terminate or incorrectly terminates a string or array with a null character or equivalent terminator.
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Executive Summary

This vulnerability in Envoy affects its mTLS certificate matcher for match_typed_subject_alt_names. Specifically, certificates that contain an embedded null byte (\0) inside an OTHERNAME SAN value may be incorrectly treated as valid matches, potentially bypassing intended certificate validation checks.

Impact Analysis

The vulnerability can lead to improper validation of mTLS certificates, allowing potentially unauthorized certificates to be accepted as valid. This could result in unauthorized access or man-in-the-middle attacks, compromising confidentiality and integrity of communications.

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