CVE-2025-66220
Title: Envoy mTLS certificate matcher null byte bypass
Other
Proof Of Concept
No public PoC currently indexed for CVE-2025-66220.
CWE Category
CWE-170
Published Date
Dec 03, 2025
Modified Date
Dec 05, 2025
Exploit Status
Not Found
Score
5.0
CVSS v3.1
Exploit Probability (EPSS)
0.16%
Vulnerability Summary
CVE-2025-66220: 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.
Impacted Vendors
Reference Links
CVSS v3.1
Source Entity
[email protected]
Severity
MEDIUM
5.0
Attack Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:L/A:N
CVSS v3.1
Source Entity
[email protected]
Severity
HIGH
7.1
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Associated Attack Patterns (CAPEC)
Total: PatternsNo specific attack patterns mapped.
Likelihood
Severity
Page /
CVE-2025-66220 Exploits & PoCs (Proof Of Concept)
No public PoCs found in our database for this CVE.
MODIFIED
Vulnerability data or affected products updated.
MODIFIED
Vulnerability data updated via NVD.
PUBLISHED
Vulnerability first announced in NVD.
Attack Vector Matrix
Access Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
CVSS Vector String
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:L/A:N
Affected Stack
No specific products linked.