Vulnerability · Published Nov 1, 2026 · Assigned by VulnCheck
CVE-2026-120243FFmpeg 2.0 through 9.0.2 Information Disclosure via G2M Kempf Palette
Medium 5.5
In plain English
A medium-severity security flaw in FFmpeg from FFmpeg. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities).
Severity (CVSS 3.1)5.5Medium
Exploit odds (30 days)0.1%top 97.9% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
FFmpeg 2.0 through 9.0.2 contains a use of uninitialized variable vulnerability in the Go2Meeting decoder that allows attackers to leak stack memory through out-of-range palette indices. Attackers can craft a G2M3/G2M4 stream with a short Kempf palette so kempf_restore_buf() copies uninitialized stack bytes, including pointers or stack guards, into decoded output.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | ffmpeg | no fix listed | DEBIAN-CVE-2026-120243 |
| Debian:13 | ffmpeg | no fix listed | DEBIAN-CVE-2026-120243 |
| Debian:14 | ffmpeg | no fix listed | DEBIAN-CVE-2026-120243 |
| Ubuntu:26.10 | ffmpeg | no fix listed | UBUNTU-CVE-2026-120243 |
Affected products (as reported)
Weakness: CWE-457 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24858 issue-tracking
- https://github.com/FFmpeg/FFmpeg/commit/edad2d0dafcf44fa315eab716fd0183ce808053b patch
- https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/g2meet.c#L1040-L1042 technical-description
- https://github.com/FFmpeg/FFmpeg product
- VulnCheck Advisory: FFmpeg 2.0 through 9.0.2 Information Disclosure via G2M Kempf Palette third-party-advisory