CVE-2026-73253

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.

• CWE-295

• https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71
• 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
• https://github.com/cesanta/mongoose/security/advisories/GHSA-jp6g-796f-39vp

Published

Aug 20, 2026

Last Modified

Sep 9, 2026

Status

Awaiting Analysis

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-73247Kestra is an open-source, event-driven orchestration platfor…8.6
• CVE-2026-73248calibre is an e-book manager. Prior to 9.12.0, calibre proce…8.5
• CVE-2026-73249calibre is an e-book manager. Prior to 9.12.0, the calibre C…7.5
• CVE-2026-7325Improper authorization in the Active Directory browsing feat…7.1
• CVE-2026-73250Notepad++ is a free and open-source source code editor. Prio…5.4
• CVE-2026-73251Mongoose is an embedded web server and network library. Prio…9.3
• CVE-2026-73254Mongoose is an embedded web server and network library. Prio…5.4
• CVE-2026-73255Mongoose is an embedded web server and network library. Prio…6.5
• CVE-2026-73256Mongoose is an embedded web server and network library. Prio…9.1
• CVE-2026-73257Mongoose is an embedded web server and network library. Prir…9.1
• CVE-2026-73258Mongoose is an embedded web server and network library. Prio…6.5
• CVE-2026-73259Mongoose is an embedded web server and network library. Prio…5.4