CVE Catalog

CVE-2026-84975

HighCVSS 7.4
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.23%

12th percentile - higher than 12% of all known CVEs

Summary

PJSIP is a free and open source multimedia communication library written in C. In 2.17 and earlier, the OpenSSL and GnuTLS backends copy DNS SubjectAltName values with string functions that recalculate their length and truncate an embedded NUL byte. With server verification enabled through --tls-verify-server, a certificate containing a DNS SubjectAltName formed from the target hostname prefix followed by an embedded NUL and an attacker-controlled suffix can be accepted for the prefix hostname.

Risk Assessment

An attacker with a certificate from a trusted issuer who can intercept the connection can impersonate the target server, complete the SIP session, and receive REGISTER credentials. This leads to account takeover and breach of communication confidentiality.

Recommendation

No fixed version is available — monitor PJSIP updates and consider using the mbedTLS backend, which is not affected. Until a patch is released, apply additional protections for TLS/SIPS connections.

Other vulnerabilities in PJSIP

See all
Original NVD description (English source)

PJSIP is a free and open source multimedia communication library written in C. In 2.17 and earlier, the OpenSSL and GnuTLS backends in pjlib/src/pj/ssl_sock_ossl.c and pjlib/src/pj/ssl_sock_gtls.c copy DNS SubjectAltName values with string functions that recalculate their length and truncate an embedded NUL byte. With server verification enabled through --tls-verify-server for the PJSIP TLS/SIPS transport, a certificate containing a DNS SubjectAltName formed from the target hostname prefix followed by an embedded NUL and an attacker-controlled suffix can therefore be accepted for the prefix hostname. An attacker who possesses such a certificate from a trusted issuer and can intercept the connection can impersonate the target server, complete the SIP session, and receive REGISTER credentials. The mbedTLS backend is not affected because it preserves the explicit string length. No fixed version is available as of this review.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS