PJSIP: Stack overflow parsing a TLS peer certificate's SubjectAltName in GnuTLS backend (CVE-2026-57163) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-57163

PJSIP: Stack overflow parsing a TLS peer certificate's SubjectAltName in GnuTLS backend

Answer in brief

CVE-2026-57163 records a Unknown severity vulnerability in PJSIP: Stack overflow parsing a TLS peer certificate's SubjectAltName in GnuTLS backend. The current sources do not mark it as known exploited. The current feed maps pjsip/pjproject (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 4, 2026Updated Sep 4, 2026Source checked Sep 4, 2026First seen by HOL Sep 4, 2026Material review Sep 4, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps pjsip/pjproject (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
pjsip/pjprojectgeneric	< c4a151af86fadd16d9480b2603eeb2abf4fb4f78	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for pjsip/pjproject.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 4, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.