Vulnerability Description
Mongoose is an embedded web server and network library. Prior to 7.23, a network attacker can impersonate a TLS server to a Mongoose client configured with a multi-certificate CA bundle. In src/tls_builtin.c, the mg_tls_init() function stores the bundle in tls->ca_bundle_der while tls->ca_der.len remains zero, and mg_tls_recv_cert() uses tls_bundle_find() to accept a Common Name match without calling mg_tls_verify_cert_signature(). A forged self-signed certificate can therefore satisfy hostname and CertificateVerify checks and enable interception, credential disclosure, traffic modification, and malicious responses. This issue is fixed in version 7.23.
Related Weaknesses (CWE)
References
- https://github.com/cesanta/mongoose/commit/2988bc9df3a5efc9539471cb7455975fa25df
- https://github.com/cesanta/mongoose/releases/tag/7.23
- https://github.com/cesanta/mongoose/security/advisories/GHSA-qj6j-2692-v2r8
- https://github.com/cesanta/mongoose/security/advisories/GHSA-qj6j-2692-v2r8
- https://github.com/cesanta/mongoose/security/advisories/GHSA-qj6j-2692-v2r8
- https://github.com/cesanta/mongoose/security/advisories/GHSA-qj6j-2692-v2r8
FAQ
What is CVE-2026-73251?
CVE-2026-73251 is a documented vulnerability. Mongoose is an embedded web server and network library. Prior to 7.23, a network attacker can impersonate a TLS server to a Mongoose client configured with a multi-certificate CA bundle. In src/tls_bu...
How severe is CVE-2026-73251?
CVSS scoring is not yet available for CVE-2026-73251. Check NVD for updates.
Is there a patch for CVE-2026-73251?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.