FFmpeg through 9.0.2 V4L2 M2M Encoder Out-of-Bounds Write in v4l2_buffers.c
- Exploited
- No known exploitation
- Fix
- Fix or patch referenced
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Uses the V4L2 M2M encoder path Affected FFmpeg versions up to 9.0.2 V4L2 driver returns buffer dimensions with alignment that can differ from the frame dimensions
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 12/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
FFmpeg through 9.0.2 contains an out-of-bounds write vulnerability in v4l2_buffer_swframe_to_buf() in libavcodec/v4l2_buffers.c because cumulative plane offsets are not checked against the V4L2 buffer length. Attackers can supply crafted video whose dimensions or padding cause unsigned wraparound in v4l2_bufref_to_buf(), making memcpy() write past the mmaped driver buffer during V4L2 M2M encoding.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure5/25Specific setups only
- Reach?/20Unknown. No tracked technology or package matched
- Severity7.3/10CVSS 7.3
- No patch0/5No signal
What would change the score
- Would score about 62 if added to CISA KEV
- Would score about 57 if CISA's SSVC rates exploitation active
- Would score about 22 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Uses the V4L2 M2M encoder path Affected FFmpeg versions up to 9.0.2 V4L2 driver returns buffer dimensions with alignment that can differ from the frame dimensionsApply the patch listed under Evidence.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- FFmpeg FFmpeg
through 9.0.2
Evidence 5
- Patch
- Report
- Repository
- Repository
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-125208
Is CVE-2026-125208 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The V4L2 M2M encoder copies frame data with memcpy() into a memory buffer mapped from the video driver, and it can write past the end of that buffer. The write goes out of bounds when the driver reports buffer dimensions with alignment padding that differs from the frame dimensions, and crafted video dimensions or padding can cause an unsigned wraparound that triggers it.Source: vulncheck.com, github.com
Which versions are affected by CVE-2026-125208?
FFmpeg: through 9.0.2.Source: cve.now feed data
Am I affected, and how do I check?
FFmpeg versions up to and including 9.0.2 are listed as affected, and the issue applies only when FFmpeg uses the V4L2 M2M encoder path with a V4L2 driver that returns aligned buffer width and height. To check, run ffmpeg -version to see the release number and look at whether the encode uses a V4L2 M2M encoder (for example h264_v4l2m2m or hevc_v4l2m2m).Source: vulncheck.com, github.com
How do I fix CVE-2026-125208?
No fixed FFmpeg release is listed in the checked facts, so no upgrade target can be confirmed from them. Check the FFmpeg project's release notes or the advisory for a fixed version before upgrading.Source: vulncheck.com, github.com