Bug 2512259 (CVE-2026-70630)

Summary: CVE-2026-70630 ffmpeg: FFmpeg: Information disclosure via uninitialized heap memory read in Screenpresso 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 in the native Screenpresso decoder allows attackers to recover sensitive memory contents. This occurs when a crafted SPV1 packet with a valid zlib stream is supplied, causing the screenpresso_decode_frame() function to fail in validating the produced byte count. Consequently, unwritten heap memory from prior allocations or frames can be copied into decoded output, potentially exposing sensitive data.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2516068, 2516069, 2516070, 2516071, 2516073    
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Description OSIDB Bzimport 2026-08-06 22:25:30 UTC 
FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native Screenpresso decoder (libavcodec/screenpresso.c) that allows attackers to recover sensitive memory contents by supplying a crafted SPV1 packet with a valid zlib stream that decompresses fewer bytes than the full frame requires. The screenpresso_decode_frame() function fails to validate the produced byte count before calling av_image_copy_plane() to copy the complete frame dimensions from the persistent ctx->inflated_buf buffer, causing unwritten heap memory from prior allocations or prior frames to be copied into decoded output and potentially exposing sensitive data such as userspace addresses from persistent decoding services.