Bug 2506936 (CVE-2026-66040)

Summary: CVE-2026-66040 ffmpeg: FFmpeg: Arbitrary code execution via crafted PNG image
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: bbrownin
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in FFmpeg's native PNG and APNG encoders. A remote attacker can exploit this heap out-of-bounds write vulnerability by providing a specially crafted PNG image containing a malicious eXIf chunk. This can lead to heap memory corruption, a process crash, and potentially allow the attacker to execute arbitrary code on the affected system.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2510583, 2510590, 2510599, 2510600, 2510601    
Bug Blocks:    

Description OSIDB Bzimport 2026-07-24 21:01:29 UTC 
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.