CVE-2026-73253
CRITICAL
9,1
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A
Description
AI Translation Available
Mongoose is an embedded web server and network library. Prior to version 7.22, an on-path network attacker with a wildcard certificate for a parent domain can impersonate deeper subdomains to a client using the built-in TLS stack. The mg_tls_verify_cert_san() and mg_tls_verify_cert_cn() functions in src/tls_builtin.c call mg_match(), whose wildcard can cross DNS label boundaries, so a pattern such as *.example.com can match foo.bar.example.com. The resulting hostname verification bypass permits interception and modification of TLS traffic. This issue is fixed in version 7.22.
295
Improper Certificate Validation
DraftCommon Consequences
Security Scopes Affected:
Integrity
Authentication
Potential Impacts:
Bypass Protection Mechanism
Gain Privileges Or Assume Identity
Applicable Platforms
Technologies:
Not Technology-Specific, Web Based, Mobile
https://github.com/cesanta/mongoose/security/advisories/GHSA-jp6g-796f-39vp
https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c1686…
https://github.com/cesanta/mongoose/pull/3611
https://github.com/cesanta/mongoose/releases/tag/7.22
https://github.com/cesanta/mongoose/security/advisories/GHSA-jp6g-796f-39vp