Out-of-bounds read via unpadded WMA extradata
Published Sep 13, 2026 · Updated Sep 13, 2026
Out-of-bounds read in libavcodec's WMA encoder in FFmpeg before 9.0 allows attackers to cause unspecified impact via unspecified vectors. The WMAV1 path allocates four bytes with av_malloc, and the WMAV2 path allocates ten zeroed bytes, but neither reserves AV_INPUT_BUFFER_PADDING_SIZE. Reachability requires WMA encoder initialization; public sources do not establish attacker control, data disclosure, or a reliably induced crash.
Summary
What happened
Out-of-bounds read in libavcodec's WMA encoder in FFmpeg before 9.0 allows attackers to cause unspecified impact via unspecified vectors. The WMAV1 path allocates four bytes with av_malloc, and the WMAV2 path allocates ten zeroed bytes, but neither reserves AV_INPUT_BUFFER_PADDING_SIZE. Reachability requires WMA encoder initialization; public sources do not establish attacker control, data disclosure, or a reliably induced crash.
The record
- CVE
- CVE-2026-52296
- Published
- Sep 13, 2026
- Updated
- Sep 13, 2026
- Vendor
- FFmpeg
- Product
- FFmpeg
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 13, 2026CVE publishedPublication date reported by the CVE source.
- Sep 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <9.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
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Technologies
Your stack
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Your stack
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