FFmpeg through 9.0.2 contains an uninitialized memory read vulnerability in decode_hybrid() in libavcodec/flashsv.c that reads past decompressed data when decoding 15-bit color pixels. Attackers can supply a crafted Flash Screen Video 2 block whose inflated data ends mid-pixel to leak heap memory into decoded output frames.
https://github.com/FFmpeg/FFmpeg/commit/16d0f7f408ba47b4091a22109d4f22f5fd57820a
https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/flashsv.c#L89
https://github.com/FFmpeg/FFmpeg
Published: 2026-11-09
Updated: 2026-11-10
Base Score: 2.1
Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:N
Severity: Low
Base Score: 3.3
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Severity: Low
Base Score: 4.8
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.00128