Vulnerability PYSEC-2026-3999

Medium Risk
MEDIUM RISK
CVSS Score: 5.3
Score Range: 4.0–6.9
Medium severity vulnerabilities (CVSS 4.0–6.9). Important issues that meaningfully reduce security confidence.
10 days ago
September 18, 2026 at 08:17 PM UTC
No summary available
0.0.1 - 0.29.0
0.0.1 - 0.29.0

Details

vLLM through 0.29.0 contains a memory corruption vulnerability in the Triton _bincount_kernel where prompt token IDs index the penalty prompt-presence bitset without bounds checking against vocabulary size. Attackers can submit multimodal audio requests with tokens equal to vocabulary size, causing out-of-bounds writes that corrupt concurrent requests' sampler state and alter repetition penalty behavior.

Impacted packages

Timeline

Published
10 days ago
September 18, 2026 at 08:17 PM UTC
Fixed (0.30.0)
7 days ago
September 22, 2026 at 05:23 AM UTC
Last Modified
2 hours ago
September 29, 2026 at 09:00 AM UTC