CVE intelligence

CVE-2026-65704

Vulnerability intelligence

Published Jul 23, 2026Sources checked Oct 27, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-65704 and is rated High severity with a CVSS score of 7.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Ubuntu Security Notices guidance

Vendor revision: Sep 9, 2026

USN-8716-1 fixed several vulnerabilities in FFmpeg.

CISA KEVNot listedBased on the latest collected catalog

EPSS0.2%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-65704?

FFmpeg through 8.1.2 contains an out-of-bounds write vulnerability that allows attackers to cause heap corruption by supplying a crafted ffconcat file processed with the -safe 0 flag.

The TY demuxer's demux_audio() function decrements packet size without bounds checking, producing a negative size value that is passed to memcpy() in shorten_decode_frame(), where conversion to size_t wraps the value to near SIZE_MAX and triggers reads beyond the source allocation and writes far beyond the Shorten decoder's bitstream buffer.

Source: NVD