CVE-2015-8661
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 · uneditedThe h264_slice_header_init function in libavcodec/h264_slice.c in FFmpeg before 2.8.3 does not validate the relationship between the number of threads and the number of slices, which allows remote attackers to cause a denial of service (out-of-bounds array access) or possibly have unspecified other impact via crafted H.264 data.
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 confidenceThe h264_slice_header_init function in FFmpeg before 2.8.3 fails to validate the relationship between the number of threads and the number of slices when parsing H.264 video streams. This allows specially crafted H.264 data to trigger an out-of-bounds array access, potentially causing denial of service or unspecified impact.
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<= 2.8.2CVSS 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
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L
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.
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Determine installed FFmpeg versionRun 'ffmpeg -version' or 'ffmpeg -version | head -1' to display the version stringAffected if The version displayed is 2.8.2 or earlier, or the full version string contains a number less than 2.8.3 (for example, 2.8.2, 2.8.1, 2.8.0, 2.7.x, 2.6.x, etc.)
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Confirm FFmpeg binary in useRun 'which ffmpeg' or 'where ffmpeg' to locate the binary being used, as multiple installations may existAffected if The detected version from step 1 corresponds to a binary that processes your H.264 content and shows version 2.8.2 or earlier
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Identify H.264 processing usageReview application logs, configuration files, or process monitoring to determine if FFmpeg is actively decoding or processing H.264 video streamsAffected if FFmpeg with version 2.8.2 or earlier is being used to parse H.264 bitstreams from untrusted or external sources
You are affected if the FFmpeg version processing your H.264 streams is 2.8.2 or earlier, since the vulnerability exists in those versions when parsing H.264 slice headers with mismatched thread/slice configurations.
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.
From vendor dataUpgrade FFmpeg to version 2.8.3 or later to obtain the patched bounds-checking code, or isolate processing of untrusted H.264 streams in sandboxed environments.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-8661 — 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-2015-8661 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
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- 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
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