The vulnerability in the ffmpeg video filtering component (vf_swaprect) arises from an out‑of‑bounds memory write. A crafted NV12 video frame with an odd width can trigger a 17‑byte memcpy into a 17‑byte buffer, corrupting the heap. If the process memory is overwritten, the attacker could potentially execute arbitrary code or cause a crash. This flaw is a classic instance of an unchecked buffer size assumption (CWE‑131) combined with an improper memory copy (CWE‑787).

FFmpeg versions 3.0 through 8.1.2 are affected. The vulnerability is present in all builds that include the vf_swaprect filter in these releases. No vendor‑specific patches have been released yet, so any system running ffmpeg in this version range is at risk.

The CVSS score of 8.5 places the issue in the high severity range, and the EPSS score of less than 1 % indicates a relatively low likelihood of exploitation at present. The vulnerability is not listed in the CISA KEV catalog. Exploitability requires the attacker to supply a malicious NV12 frame to ffmpeg, which could occur when the software processes untrusted video streams or media files. The crafted frame triggers a 17‑byte memcpy into a 17‑byte buffer, corrupting heap memory and causing a process crash with potential for code execution. Therefore, the risk is significant for systems that process untrusted NV12 frames, but the overall probability of exploitation remains limited by current usage patterns.