CVE-2026-75143 FFmpeg CVE debrief

Who should care

Organizations and developers using FFmpeg in their applications, especially those involving RIST protocol communication, should be aware of this vulnerability and take steps to mitigate it. This includes reviewing and updating FFmpeg installations, monitoring for suspicious traffic, and applying patches. Security teams and vulnerability management teams should prioritize patching and review compensating controls for exposed systems.

Technical summary

The FFmpeg library before commit 1c10bcc contains a heap buffer overflow in the RIST protocol reader. The issue arises from the librist_read() function ignoring its size argument and copying the full received payload length into the caller-provided destination buffer. This can be exploited by a remote RIST sender sending a packet with a payload exceeding the caller buffer size, potentially leading to remote code execution. Affected systems include those using FFmpeg for RIST protocol communication.

Defensive priority

Organizations using FFmpeg should prioritize patching to prevent potential remote code execution via the RIST protocol reader.

Recommended defensive actions

• Apply the patch from commit 1c10bcc2e17255dacb717a25ab3db142ce390602
• Review and update FFmpeg installations to ensure the patched version is used
• Monitor for suspicious RIST protocol traffic
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record indicates a heap buffer overflow in the RIST protocol reader of FFmpeg before commit 1c10bcc. The issue is reachable via the async:rist:// URL scheme. A remote RIST sender can trigger the overflow by sending a packet whose payload exceeds the caller buffer size. To verify, defenders should review the RIST protocol implementation, check for patch application, and monitor for suspicious RIST protocol traffic.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.