VulnerabilityAnalyzed

CVE-2026-65704

FFmpeg through 8.1.2 contains an out-of-bounds write vulnerability that allows attackers to cause heap corruption by supplying a crafted ffconcat file processed with the -safe 0 flag.

HIGH 7.3EPSS 0.12%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

FFmpeg through 8.1.2 contains an out-of-bounds write vulnerability that allows attackers to cause heap corruption by supplying a crafted ffconcat file processed with the -safe 0 flag. The TY demuxer's demux_audio() function decrements packet size without bounds checking, producing a negative size value that is passed to memcpy() in shorten_decode_frame(), where conversion to size_t wraps the value to near SIZE_MAX and triggers reads beyond the source allocation and writes far beyond the Shorten decoder's bitstream buffer.

CVSS 4.0: 7.3 HIGHCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.12% probability · 2th percentile
CISA KEV: Not listed
Weakness: CWE-191, CWE-787
Affected: ffmpeg/ffmpeg
Source: disclosure@vulncheck.com

References

https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/de771bd52774a52d45b0e2c82e56995a1ef40df7Patch
https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23767Issue Tracking, Patch
https://www.vulncheck.com/advisories/ffmpeg-out-of-bounds-write-via-ty-demuxer-and-shorten-decoderThird Party Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.