FFmpeg: Heap buffer overflow in Huffyuv encoder (CVE-2026-125256)
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.
CVE search metadata
CVE search record: CVE-2026-125256. Severity: high. CVSS: 7.0. KEV: no. Product: FFmpeg (through 9.0.2). Brief: FFmpeg: Heap buffer overflow in Huffyuv encoder (CVE-2026-125256). Brief link: https://feed.craftedsignal.io/briefs/2026-11-ffmpeg-heap-overflow-add5b4c7/
Triage facts
Revision 1- Applicability
- FFmpeg (through 9.0.2)
- Evidence
- Unknown
- Severity
- High
- Sources
- 1 public source
- Freshness
- Revision 1Nov 9, 21:58 UTC
- Vulnerabilities
- 1 CVE
- Source quality
- A2Roughly even chance
FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in the ff_llvidenc_diff_bytes_rvv() function. 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 and resulting in heap memory corruption.