Bug 2570659 (CVE-2026-125250)

Summary: CVE-2026-125250 ffmpeg: ffmpeg: Arbitrary code execution via heap-based buffer overflow in GIF encoder
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
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. A heap-based buffer overflow vulnerability exists in the GIF encoder because memory allocated for processing frames is sized from the initial frame and does not account for frame line sizes that increase mid-stream. By providing a specially crafted video file for transcoding, an attacker could trigger memory corruption, potentially leading to arbitrary code execution or an application crash resulting in a denial of service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-11-10 20:13:52 UTC 
FFmpeg through 9.0.2 contains a heap buffer overflow in the GIF encoder's gif_image_write_image() in libavcodec/gif.c because shrunk_buf is sized from the first frame's linesize. Attackers can supply PAL8 video whose frame linesize grows mid-stream, causing remap_frame_to_palette() to write past shrunk_buf and corrupt the heap during GIF transcoding.