Incorrect Calculation of Buffer Size in vLLM - CVE-2026-44223
Published: May 1, 2026
Vulnerability identifier: #VU128747
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-2026-44223
CWE-ID: CWE-131
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to incorrect calculation of buffer size in the extract_hidden_states speculative decoding proposer when processing requests with sampling penalty parameters. A remote user can send a specially crafted request with a penalty parameter to cause a denial of service.
Only deployments configured with extract_hidden_states speculative decoding are vulnerable.
Affected software
vLLM
How to mitigate CVE-2026-44223
Install security update from vendor's website.
vLLM - update to 0.20.0