Heap-based buffer overflow in vLLM - CVE-2026-109311
Published: November 9, 2026 / Updated: November 10, 2026
Vulnerability identifier: #VU162993
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-109311
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a low-privileged remote attacker to crash the vLLM API process, denying service to all users of the server.
The vulnerability exists due to unvalidated audio reaching a heap-based buffer overflow in a vulnerable FFmpeg IAMF parser when speech transcription falls back from soundfile to PyAV. A low-privileged remote attacker can repeatedly upload crafted IAMF files to /v1/audio/transcriptions to corrupt the heap and terminate the process.
Affected software
vLLM
How to mitigate CVE-2026-109311
Install security update from vendor's website.
vLLM - update to 0.29.0