CVE-2026-65705

Name of the Vulnerable Software and Affected Versions FFmpeg versions 3.4 through 8.1.2

Description An out-of-bounds write issue exists in the vf floodfill video filter. This occurs when a dynamically sized video stream is supplied while filtergraph reinitialization is disabled via -reinit filter 0. The config input() function allocates the points traversal stack based on the initial frame dimensions; if a subsequent larger frame is processed, the filter frame() function performs flood-fill neighbor pushes beyond the original allocation boundary. This leads to heap corruption, which can cause a process crash or potentially allow arbitrary code execution depending on the heap layout and process hardening.

Recommendations Update FFmpeg to a version later than 8.1.2. As a temporary mitigation, avoid using the vf floodfill filter with the -reinit filter 0 option when processing dynamically sized video streams.