Bug 2570492 (CVE-2026-125218)

Summary: CVE-2026-125218 ffmpeg: ffmpeg: Arbitrary code execution via mid-stream resolution changes in APNG encoder
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: bbrownin
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in FFmpeg. An attacker could exploit this vulnerability by submitting a specially crafted media file with dynamic frame resolution changes to an application processing Animated Portable Network Graphics (APNG) content. This triggers a heap-based buffer overflow in the encoder. Successful exploitation can lead to arbitrary code execution, memory corruption, or an application crash resulting in a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-11-10 20:02:14 UTC
FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in the APNG encoder's encode_apng() function in libavcodec/pngenc.c when frame size changes mid-stream. Attackers can supply crafted media whose resolution grows mid-stream, causing APNG_DISPOSE_OP_BACKGROUND memset writes past prev_frame and crashing or corrupting heap memory in transcoding applications.