{"id":"CVE-2026-125256","state":"PUBLISHED","title":"FFmpeg through 9.0.2 Heap Buffer Overflow via RISC-V Vector diff_bytes Routine","description":"FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in ff_llvidenc_diff_bytes_rvv() that allows attackers to corrupt heap memory by triggering negative length values in the Huffyuv encoder. Attackers can supply RGB video narrower than 8 or 16 pixels for huffyuv transcoding on RVV-enabled RISC-V builds, causing writes past the encoder's temp buffer.","publishedAt":"2026-11-09T19:12:00.407Z","updatedAt":"2026-11-09T19:12:00.407Z","severity":{"score":7.3,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["FFmpeg FFmpeg"],"affected":[{"vendor":"FFmpeg","product":"FFmpeg","packageURL":"pkg:github/ffmpeg/ffmpeg","defaultStatus":"unaffected","versions":[{"version":"7.0","status":"affected","lessThanOrEqual":"9.0.2","versionType":"custom"}],"repo":"https://code.ffmpeg.org/FFmpeg/FFmpeg"}],"references":["https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25573","https://github.com/FFmpeg/FFmpeg/commit/1f7bdea654a8a9a1761759e22d83943371cff21f","https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/riscv/llvidencdsp_rvv.S#L26","https://github.com/FFmpeg/FFmpeg","https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-buffer-overflow-via-risc-v-vector-diff-bytes-routine"],"weaknesses":["CWE-787"],"ingestedAt":"2026-11-09T19:20:06.412Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/125xxx/CVE-2026-125256.json","commit":"23dd7329a2fc1587153d555b09cffa1a3e08ef0f","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-125256","state":"PUBLISHED","datePublished":"2026-11-09T19:12:00.407Z","dateUpdated":"2026-11-09T19:12:00.407Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-11-09T18:15:32.104Z"},"containers":{"cna":{"title":"FFmpeg through 9.0.2 Heap Buffer Overflow via RISC-V Vector diff_bytes Routine","descriptions":[{"lang":"en","value":"FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in ff_llvidenc_diff_bytes_rvv() that allows attackers to corrupt heap memory by triggering negative length values in the Huffyuv encoder. 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