CVE-2026-58049

EUVD-2026-39969

28.06.2026, 02:16

FFmpeg's RASC video decoder (decode_dlta in libavcodec/rasc.c) performs 32-bit reads and writes at the row cursor before the NEXT_LINE row-boundary check and validates the DLTA region in pixel rather than byte units, so a DLTA run on a PAL8 frame can access several bytes past the row allocation. A crafted media stream using the RASC FourCC, decoded by libavcodec, triggers a bitstream-controlled out-of-bounds heap write and adjacent out-of-bounds read, leading to memory corruption.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	8.6 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

Awaiting analysis

This vulnerability is currently awaiting analysis.

Base Score

CVSS 3.x

EPSS Score

Percentile: 19%

Debian Releases

Debian Product

Codename

ffmpeg

bookworm	vulnerable
bookworm (security)	vulnerable
bullseye	vulnerable
bullseye (security)	vulnerable
forky	vulnerable
sid	vulnerable
trixie	vulnerable
trixie (security)	vulnerable

Common Weakness Enumeration

CWE-787 - Out-of-bounds Write
The software writes data past the end, or before the beginning, of the intended buffer.

References

https://github.com/FFmpeg/FFmpeg/blob/master/libavcodec/rasc.c

https://github.com/bikini/exploitarium/tree/main/ffmpeg-rasc-dlta-calc-poc

https://www.vulncheck.com/advisories/ffmpeg-out-of-bounds-write-in-rasc-decoder-decode-dlta