What’s Vulnerable › Vulnerabilities

CVE-2026-66037: FFmpeg IAMF Demuxer Uncontrolled Resource Consumption via mix_presentation_obu()

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-24 · updated 2026-08-07
• Weakness: CWE-770

Description

FFmpeg through 8.1.2, fixed in commit 5d7112c, contains an uncontrolled resource consumption vulnerability in the IAMF demuxer that allows an unauthenticated attacker to cause multi-gigabyte memory allocation from a 17-byte input file by supplying a crafted count_label field. The mix_presentation_obu() function in libavformat/iamf_parse.c calls av_calloc(count_label, sizeof(*language_label)) with an attacker-controlled value before validating available OBU data, enabling an allocation amplification of approximately 126 million bytes per input byte that exhausts process memory or triggers an OOM-kill during format probing.

Affected products

• FFmpeg: through 8.1.2

References

• https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/86708357d126af84c16f80d9c57335d1e8c845c5
• https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23627
• https://www.vulncheck.com/advisories/ffmpeg-iamf-demuxer-uncontrolled-resource-consumption-via-mix-presentation-obu

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