Vulnerability Description
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 Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ffmpeg | Ffmpeg | <= 8.1.2 |
Related Weaknesses (CWE)
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/b506fafec9a19fcbc2be5271875fd4a63d6Patch
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23786Issue TrackingPatch
- https://www.vulncheck.com/advisories/ffmpeg-heap-out-of-bounds-write-via-png-apnThird Party Advisory
FAQ
What is CVE-2026-66040?
CVE-2026-66040 is a vulnerability with a CVSS score of 8.8 (HIGH). 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 ...
How severe is CVE-2026-66040?
CVE-2026-66040 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-66040?
Check the references section above for vendor advisories and patch information. Affected products include: Ffmpeg Ffmpeg.