Heap overwrite via unchecked RIST payload copy
Published Aug 19, 2026 · Updated Aug 21, 2026
Heap buffer overflow in FFmpeg before commit 1c10bcc allows remote attackers to crash the process via crafted RIST packets. In libavformat/librist.c, librist_read() copies the full received payload into the caller buffer and ignores the size argument that should bound the copy; the async:rist wrapper can pass a smaller destination buffer than the packet payload. Exposure requires FFmpeg to read from an attacker-controlled RIST sender over the network; public records describe a remote heap overwrite but do not disclose a demonstrated exploit chain beyond memory corruption and process interruption.
Summary
What happened
Heap buffer overflow in FFmpeg before commit 1c10bcc allows remote attackers to crash the process via crafted RIST packets. In libavformat/librist.c, librist_read() copies the full received payload into the caller buffer and ignores the size argument that should bound the copy; the async:rist wrapper can pass a smaller destination buffer than the packet payload. Exposure requires FFmpeg to read from an attacker-controlled RIST sender over the network; public records describe a remote heap overwrite but do not disclose a demonstrated exploit chain beyond memory corruption and process interruption.
The record
- CVE
- CVE-2026-75143
- Published
- Aug 19, 2026
- Updated
- Aug 21, 2026
- Vendor
- FFmpeg
- Product
- FFmpeg
- Classifications
- CWE-122, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 19, 2026CVE publishedPublication date reported by the CVE source.
- Aug 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <1c10bcc2e17255dacb717a25ab3db142ce390602
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- FFmpeg RIST Protocol Heap Buffer Overflowproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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