CVE-2026-57163: CWE-121: Stack-based Buffer Overflow in pjsip pjproject
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.
CVE-2026-57163: CWE-121: Stack-based Buffer Overflow in pjsip pjproject
Description
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.
CVSS v4.0
Score 8.8high
Weaknesses
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-24T01:47:55.284Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a9afe70acd9273b49f0e673
Added to database: 09/04/2026, 17:22:56 UTC
Last updated: 09/04/2026, 18:07:12 UTC
Views: 5
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