PT-2026-64416 · FFmpeg · Ffmpeg

Adrian Junge · CVE-2026-66040 · Published 2026-07-24 · Updated 2026-07-24

NVD

CVSS v3.1

8.8

High

Base vector

AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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.

Fix

Heap Based Buffer Overflow

Weakness Enumeration

CWE-122

Related Identifiers

CVE-2026-66040

Affected Products

Ffmpeg

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-66040 · Security Note
• https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/b506fafec9a19fcbc2be5271875fd4a63d6615bc · Patch
• https://vulncheck.com/advisories/ffmpeg-heap-out-of-bounds-write-via-png-apng-exif-encoder · Note
• https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23786 · Note