CVE-2026-75141

FFmpeg before commit acf5d7c contains a heap buffer overflow in the hvcC box writer. When writing an HEVC configuration record with more NAL units of a single type than the count field can represent, the NAL unit count overflows, causing a heap buffer overflow. A crafted HEVC input file triggers the overflow during muxing.

CVSS 4.0

8.5CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

7.8CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 9% of CVEs (scores of 2026-10-25)

CWE

CWE-122

Published

2026-08-19

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

References

• https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/acf5d7cdc1f9ae8752c23e1ea8d7f355ed780781
• https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24088
• https://www.vulncheck.com/advisories/ffmpeg-heap-buffer-overflow-in-hvcc-box-writer-via-hevc-muxing

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