Buffer overflow in Pjsip Pjproject

CVE-2026-26967

PJSIP is a free and open source multimedia communication library written in C. In versions 2.16 and below, there is a critical Heap-based Buffer Overflow vulnerability in PJSIP's H.264 unpacketizer. The bug occurs when processing malformed SRTP packets, where the unpacketizer reads a 2-byte NAL unit size field without validating that both bytes are within the payload buffer bounds. The vulnerability affects applications that receive video using H.264. A patch is available at https://github.com/pjsip/pjproject/commit/f821c214e52b11bae11e4cd3c7f0864538fb5491.

Vulnerability class: Buffer Overflow

EPSS: 0.003 (21.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-26967?
CVE-2026-26967 is a medium-severity vulnerability in Pjsip Pjproject, classified under Heap-based Buffer Overflow. CVSS score: 5.3/10. Published 2026-02-20.
How severe is CVE-2026-26967?
Medium severity. CVSS v3 base score is 5.3 out of 10.