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Vulnerabilities

Vulnerability · CVE-2026-84975

PJSIP is a free and open source multimedia communication library written in C.

Published Sep 18, 2026 · catalog updated Oct 20, 2026 · PJSIP is a free

Check if you run it

No confirmed exploitation is on record for CVE-2026-84975. EPSS is 0.23%. Act only if a listed version of PJSIP is a free is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (PJSIP is a free).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.4
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.23%
Remediation
Version ranges on file
Affected products
cpe teluu/pjsip

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe teluu/pjsip<= 2.17

How to fix CVE-2026-84975

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-84975. EPSS is 0.23%. Act only if a listed version of PJSIP is a free is installed.

Which versions are affected?

Compare what you have installed with <= 2.17. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-295: Improper Certificate Validation; CWE-297. EPSS 0.23%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 18, 2026 · NIST NVD

    Detected

    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 t

  2. Oct 20, 2026 · NIST NVD

    Updated

    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 t

Sources

  • CVE.orgVulnerability recordCVE-2026-84975

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-84975

    30-day exploitation probability 0.23%

    first.org
  • NIST NVDVulnerability recordCVE-2026-84975

    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

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 23, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.