Use After Free in Ffmpeg
CVE-2026-125265
FFmpeg through 9.0.2 contains a use-after-free vulnerability in libavcodec/nvdec.c because ff_nvdec_start_frame() fails to reset ctx->bitstream after slice errors. Attackers can supply crafted video that abandons a picture before end_frame, causing cuvidDecodePicture() to read freed heap memory, crashing applications or exposing stale heap contents.
Vulnerability class: Use-After-Free
Published .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:H.
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/25231 (issue-tracking)
- github.com/FFmpeg/FFmpeg/commit/03cd7851955c023f1ff4c8a495d47e996d01485a (patch)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/nvdec.c (technical-description)
- github.com/FFmpeg/FFmpeg (product)
- www.vulncheck.com/advisories/ffmpeg-through-9.0.2-use-after-free-via-nvdec-stal… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-125265?
- CVE-2026-125265 is a medium-severity vulnerability in Ffmpeg, classified under Use After Free. CVSS score: 5.3/10. Published 2026-11-09.
- How severe is CVE-2026-125265?
- Medium severity. CVSS v3 base score is 5.3 out of 10.