Bug 2512256 (CVE-2026-70629)

Summary: CVE-2026-70629 ffmpeg: FFmpeg: Information disclosure via uninitialized heap memory read in RSCC decoder
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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 uninitialized heap memory read vulnerability exists in the native RSCC decoder. An attacker can supply a crafted video file with a compressed tile that decompresses fewer bytes than required. This leads to the unwritten portion of an intermediate buffer being copied into the decoded frame, potentially exposing data from prior heap allocations or previous decoded frames.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2516124, 2516125, 2516126, 2516127, 2516128    
Bug Blocks:    

Description OSIDB Bzimport 2026-08-06 22:25:17 UTC 
FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native RSCC decoder (libavcodec/rscc.c) that allows attackers to disclose heap memory contents by supplying a crafted video file with a compressed tile that decompresses fewer bytes than the declared tile geometry requires. When rscc_decode_frame() calls av_image_copy_plane() without validating the decompressed byte count against the tile dimensions, the unwritten suffix of the persistent intermediate buffer ctx->inflated_buf is copied into the decoded frame, potentially exposing data from prior heap allocations or previous decoded frames in persistent decoding services.