Is CVE-2026-57163 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-57163 being exploited in the wild.

How severe is CVE-2026-57163?

Critical severity, with a CVSS score of 9.1, published 4 September 2026.

Which products and versions are affected?

PJSIP Pjproject 2.17 and earlier.

Is there a fix for CVE-2026-57163?

A patch was published on 2026-09-04: commit c4a151a Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-57163 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-57163?

Check whether you run PJSIP Pjproject or Teluu Pjsip at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-57163: PJSIP stack buffer overflow in GnuTLS TLS backend

CVE-2026-57163 · Severity: critical · CVSS 9.1 · Published 2026-09-04

PJSIP is an open-source multimedia communication library used for VoIP and real-time communication applications. A flaw in its GnuTLS backend allows an attacker to trigger a stack buffer overflow by presenting a crafted TLS certificate during the initial handshake, before any application-level authentication occurs. This can lead to application crashes or, in worst-case scenarios, arbitrary code execution.

Technologies: PJSIP Pjproject, Teluu Pjsip. Vendors: PJSIP, Teluu.

Quick answers

Is CVE-2026-57163 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-57163 being exploited in the wild.
How severe is CVE-2026-57163?: Critical severity, with a CVSS score of 9.1, published 4 September 2026.
Which products and versions are affected?: PJSIP Pjproject 2.17 and earlier.
Is there a fix for CVE-2026-57163?: A patch was published on 2026-09-04: commit c4a151a Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-57163 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-57163?: Check whether you run PJSIP Pjproject or Teluu Pjsip at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a stack-based buffer overflow (CWE-121) in the tls_cert_get_info() function within ssl_sock_gtls.c. The root cause is an incorrect buffer-size value (512 bytes) passed to gnutls_x509_crt_get_subject_alt_name() when the actual output buffer is only 256 bytes, causing an oversized SubjectAltName entry to overflow the stack. The attack is network-triggered during TLS handshake—a malicious server can attack a connecting client, or a malicious client can attack a server requesting certificates—requiring no prior authentication. Exploitation can result in denial of service or memory corruption leading to code execution. Only GnuTLS-compiled builds (--with-gnutls) are affected; OpenSSL and Apple SecureTransport/Network.framework backends are not vulnerable. The fix is available via commit c4a151a, which corrects the buffer-size calculation to sizeof(out) - 1 on every iteration.

Affected products

PJSIP PJPROJECT 2.17 and earlier

Timeline

2026-09-04: disclosed
2026-09-04: patched: commit c4a151a

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.