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High 8.8Published Jul 24, 2026

CVE-2026-66040FFmpeg Heap Out-of-Bounds Write via PNG/APNG eXIf Encoder

Updated under an hour ago ()

Does this affect you?

It affects FFmpeg. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

FFmpeg through 8.1.2, fixed in commit b506faf, contains a heap out-of-bounds write vulnerability in the native PNG and APNG encoders that allows remote attackers to corrupt heap memory by supplying a crafted PNG image with a malicious eXIf chunk. Attackers can craft an eXIf chunk where multiple IFD entries reference the same large value payload, causing canonical serialization to expand the output far beyond the undersized allocation estimated by add_exif_profile_size(), resulting in png_write_chunk() writing tens of thousands of bytes past the buffer boundary, leading to deterministic heap corruption, process crash, and potentially arbitrary code execution.

CVSS
8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-122
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
VulnCheck
NVD analysis
Analyzed
Record last updated
Jul 28, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
FFmpeg FFmpeg
ffmpeg:ffmpeg (from the name)
through 8.1.2; b506fafec9a19fcbc2be5271875fd4a63d6615bc not affected
CNA record
ffmpeg ffmpeg
ffmpeg:ffmpeg
through 8.1.2
NVD

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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