Libav: FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native RSCC decoder… (CVE-2026-70629)
FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native RSCC decoder. This flaw allows an attacker to disclose heap memory contents by providing a crafted video file with a compressed tile that decompresses fewer bytes than expected. The vulnerability arises because the decompressed byte count is not validated against the tile dimensions before copying data, potentially exposing data from prior heap allocations or previous decoded frames.
AI Analysis
Technical Summary
The vulnerability exists in FFmpeg's native RSCC decoder (libavcodec/rscc.c) in versions >=3.0 and <9.0. When the function rscc_decode_frame() calls av_image_copy_plane(), it does not verify that the decompressed byte count matches the declared tile geometry. This leads to copying uninitialized memory from the persistent intermediate buffer ctx->inflated_buf into the decoded frame, resulting in potential disclosure of heap memory contents.
Potential Impact
An attacker can disclose sensitive heap memory contents by supplying a specially crafted video file that triggers the uninitialized memory read. This may expose data from prior heap allocations or previous decoded frames in persistent decoding services. The vulnerability does not affect integrity or availability, only confidentiality.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the available data. Users should monitor vendor advisories for updates and consider avoiding processing untrusted RSCC-encoded video files until a fix is available.
Libav: FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native RSCC decoder… (CVE-2026-70629)
Description
FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native RSCC decoder. This flaw allows an attacker to disclose heap memory contents by providing a crafted video file with a compressed tile that decompresses fewer bytes than expected. The vulnerability arises because the decompressed byte count is not validated against the tile dimensions before copying data, potentially exposing data from prior heap allocations or previous decoded frames.
CVSS v3.1
Score 5.5medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability exists in FFmpeg's native RSCC decoder (libavcodec/rscc.c) in versions >=3.0 and <9.0. When the function rscc_decode_frame() calls av_image_copy_plane(), it does not verify that the decompressed byte count matches the declared tile geometry. This leads to copying uninitialized memory from the persistent intermediate buffer ctx->inflated_buf into the decoded frame, resulting in potential disclosure of heap memory contents.
Potential Impact
An attacker can disclose sensitive heap memory contents by supplying a specially crafted video file that triggers the uninitialized memory read. This may expose data from prior heap allocations or previous decoded frames in persistent decoding services. The vulnerability does not affect integrity or availability, only confidentiality.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the available data. Users should monitor vendor advisories for updates and consider avoiding processing untrusted RSCC-encoded video files until a fix is available.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-824f-v6qw-342h
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-70629"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6a75739bbf8831d539d91c27
Added to database: 08/07/2026, 05:56:43 UTC
Last enriched: 09/13/2026, 15:03:32 UTC
Last updated: 09/21/2026, 22:01:37 UTC
Views: 36
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