CVE-2026-40962
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedFFmpeg before 8.1 has an integer overflow and resultant out-of-bounds write via CENC (Common Encryption) subsample data to libavformat/mov.c.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceFFmpeg before version 8.1 contains an integer overflow vulnerability in libavformat/mov.c when processing CENC (Common Encryption) subsample data from MP4/MOV files. The overflow leads to an out-of-bounds write, allowing heap corruption that can be exploited for remote code execution via specially crafted encrypted media files.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 8.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Determine installed FFmpeg versionRun `ffmpeg -version` and examine the version number in the outputAffected if Version is earlier than 8.1 (such as 8.0.x, 7.x, 6.x, or older)
-
Verify CENC-encrypted MP4/MOV file processingIdentify if FFmpeg is used to process encrypted (DRM-protected) MP4 or MOV files. Review media processing scripts, workflows, or application logs for encrypted media handling.Affected if FFmpeg versions before 8.1 process CENC-encrypted MP4 or MOV files
-
Inspect media files for CENC encryptionUse ffprobe to examine MP4/MOV files for encryption metadata. Run `ffprobe -show_streams -i <filename>` and check for encryption, protection scheme, or DRM-related stream information.Affected if Media files contain CENC encryption and are processed by vulnerable FFmpeg versions
A system is affected if it runs FFmpeg versions earlier than 8.1 and processes CENC-encrypted MP4 or MOV files, which triggers the vulnerable subsample parsing code path in libavformat/mov.c.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped8.1
Upgrade FFmpeg to version 8.1 or later to obtain the fix for the integer overflow vulnerability in CENC subsample parsing.
FFmpeg 8.1 or later
- Upgrade FFmpeg to version 8.1 or later to obtain the fix for the integer overflow vulnerability in libavformat/mov.c (CENC subsample handling)
- Verify the installed FFmpeg version using: ffmpeg -version
- If running a version older than 8.1, obtain the latest release from https://ffmpeg.org/download.html or your distribution's package manager
- After upgrading, test that FFmpeg properly handles CENC-encrypted media files to confirm the fix is applied
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing8.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,288.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-40962 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-40962 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data