CVE-2026-12706: ffmpeg Use After Free

Vulnerability summary

CVE-2026-12706 is a medium (CVSS 6.5) Use After Free vulnerability in ffmpeg. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 38% of scored vulnerabilities.

Timeline

1. 19-06-2026
   PublishedVulnerability first disclosed.
2. 22-06-2026
   Last modifiedVulnerability information updated.

Description

A use-after-free vulnerability was found in FFmpeg's RASC video decoder. The decode_move() function initializes a read pointer into a decompressed buffer, but a subsequent reallocation of that same buffer during move-table processing leaves the pointer dangling. An attacker could exploit this by providing a specially crafted AVI file containing a malicious RASC video stream. When a user opens or plays the file, the decoder reads from freed heap memory, which could lead to a denial of service (crash).

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.