Vulnerability in Ffmpeg
CVE-2026-125243
FFmpeg through 9.0.2 contains an uninitialized memory disclosure vulnerability in ff_jpegls_decode_picture() in libavcodec/jpeglsdec.c, which decodes 16-bit line-interleaved JPEG-LS scans as 8-bit samples. Attackers can supply a crafted single-component JPEG-LS image with the ILV byte set to 1, causing decoded GRAY16 frames to expose leftover heap memory.
Published .
CVSS v3 metric
CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25303 (issue-tracking)
- github.com/FFmpeg/FFmpeg (product)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/jpeglsdec.c (technical-description)
- github.com/FFmpeg/FFmpeg/commit/60bc31fcf6543505e6d2fc1a9399cca95f54ba4d (patch)
- www.vulncheck.com/advisories/ffmpeg-through-9.0.2-uninitialized-memory-disclosu… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-125243?
- CVE-2026-125243 is a low-severity vulnerability in Ffmpeg, classified under Use of Uninitialized Resource. CVSS score: 3.3/10. Published 2026-11-09.
- How severe is CVE-2026-125243?
- Low severity. CVSS v3 base score is 3.3 out of 10.