Stack Buffer Overflow in PJSIP GnuTLS Implementation

CVE-2026-57163

What is CVE-2026-57163?

A stack buffer overflow vulnerability exists within the PJSIP multimedia communication library when using the GnuTLS TLS backend. This issue arises specifically during the parsing of the Subject Alternative Name extension of peer certificates. An attacker situated in a network position can exploit this vulnerability by presenting a crafted certificate during a TLS handshake with a client or server. The flaw is triggered due to an improper buffer size, allowing an oversized SubjectAltName entry to overflow beyond the fixed-size stack buffer. Consequently, this could lead to unexpected application terminations or control flow hijacking, posing significant risks to the integrity and security of the application. This issue has been mitigated in the latest commit.

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