PJSIP pjproject GnuTLS TLS backend ssl_sock_gtls.c tls_cert_get_info stack-based overflow

Summaryinfo

A vulnerability has been found in PJSIP pjproject and classified as critical. The impacted element is the function tls_cert_get_info of the file ssl_sock_gtls.c of the component GnuTLS TLS backend. Performing a manipulation results in stack-based overflow. This vulnerability is reported as CVE-2026-57163. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability classified as critical has been found in PJSIP pjproject (the affected version unknown). This affects the function tls_cert_get_info of the file ssl_sock_gtls.c of the component GnuTLS TLS backend. The manipulation with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

PJSIP is a free and open source multimedia communication library written in C. Prior to commit c4a151a, a stack buffer overflow exists in the GnuTLS TLS backend when parsing the Subject Alternative Name extension of a peer certificate (tls_cert_get_info() in ssl_sock_gtls.c). Only GnuTLS builds are affected (--with-gnutls); OpenSSL and Apple SecureTransport/Network.framework builds are not affected. While extracting certificate information after a TLS handshake, an incorrect buffer-size value can cause an oversized SubjectAltName entry to be written past the end of a fixed-size stack buffer. A network-positioned attacker presenting a crafted certificate — a malicious server to a connecting client, or a malicious client to a server that requests certificates — can trigger this during the TLS handshake, before any SIP-level authentication. Impact may range from unexpected application termination to control flow hijack/memory corruption. This issue has been patched via commit c4a151a.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-57163 since 06/24/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit.

Applying the patch c4a151af86fadd16d9480b2603eeb2abf4fb4f78 is able to eliminate this problem.

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Productinfo

Type

• Project Management Software

Vendor

• PJSIP

Name

• pjproject

License

• open-source

Website

• Product: https://github.com/pjsip/pjproject/

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