CVE-2026-66040
highpriority · track · 35EPSS 0.008 · 56 %ileDEEUUSEPSS · scored 2026-10-27
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.3–8.8
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (10)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-2526ffmpeg: Mehrere SchwachstellenDeutsch2026-07-26csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in ffmpeg ausnutzen, um eine Speicherbeschädigung herbeizuführen, beliebigen Code auszuführen, einen Denial-of-Service-Zustand auszulösen oder vertrauliche Informationen offenzulegen.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (9)
External citations — patches, advisories, analysis.
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/b506fafec9a19fcbc2be5271875fd4a63d6615bccnnvd
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23786cnnvd
- https://www.vulncheck.com/advisories/ffmpeg-heap-out-of-bounds-write-via-png-apng-exif-encodercnnvd
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/b506fafec9a19fcbc2be5271875fd4a63d6615bcenisa_euvd
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23786enisa_euvd
- https://www.vulncheck.com/advisories/ffmpeg-heap-out-of-bounds-write-via-png-apng-exif-encoderenisa_euvd
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/b506fafec9a19fcbc2be5271875fd4a63d6615bcPatchnvd
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23786Issue TrackingPatchnvd
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