CVE-2026-77396

PJSIP is a free and open source multimedia communication library written in C. In 2.17 and earlier, the PJSIP AVI parser in pjmedia/src/pjmedia/avi_player.c uses an input-file video chunk length as the number of bytes copied into a frame buffer whose capacity is derived from the declared media dimensions. A crafted AVI file can therefore cause an attacker-controlled out-of-bounds write past the heap allocation when an application plays the file or pulls its frames. The existing size assertion does not protect production release builds, where assertions are disabled. Typical local playback can crash the process, while applications that accept untrusted AVI sources expose a stronger memory-corruption condition. No fixed version is available as of this review.

  • Published Sep 18, 2026
  • CVSS 6.9 medium
  • 0.2% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-77396 at the National Vulnerability Database