FFmpeg through 9.0.2 Heap Overflow via QSV Encoder submit_frame()
Affects FFmpeg through 9.0.2 when Intel Quick Sync (QSV) encoders transcode input whose resolution grows mid-stream without rescaling. No fixed version is listed in the checked facts.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- 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. Intel Quick Sync (QSV) encoders are used for transcoding Input resolution increases mid-stream
- 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 a heap overflow vulnerability in libavcodec/qsvenc.c that allows attackers to corrupt memory by reusing an undersized pooled QSVFrame buffer when input dimensions increase. Attackers can supply crafted input whose resolution grows mid-stream, transcoded with Intel Quick Sync encoders without rescaling, to crash the application or corrupt heap memory.
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.
Intel Quick Sync (QSV) encoders are used for transcoding Input resolution increases mid-streamApply 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.
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Questions about CVE-2026-125235
Is CVE-2026-125235 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?
A heap overflow in FFmpeg's QSV encoder submit_frame() function can corrupt heap memory. The checked facts say this can crash the application or corrupt memory.Source: vulncheck.com
Which versions are affected by CVE-2026-125235?
FFmpeg: through 9.0.2.Source: cve.now feed data
Am I affected, and how do I check?
All FFmpeg versions through 9.0.2 are listed as affected. The bug involves Intel Quick Sync (QSV) encoders transcoding input whose resolution increases mid-stream without rescaling. To check, look for QSV encoder use in your FFmpeg command lines, such as encoders named like h264_qsv or hevc_qsv.Source: vulncheck.com
How do I fix CVE-2026-125235?
The checked facts do not name a fixed version, so no specific upgrade target can be given. Check the FFmpeg project's release notes for a release newer than 9.0.2 that addresses this issue.Source: vulncheck.com