CVE-2026-93840: vllm · Improper Validation of Array Index
Affects vllmSource CVE Database V5
Not known to be exploited · CVSS 6.3 Medium : upgrade to 0.29.0 when convenient.
Data as of 2 Nov 2026, 22:58 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.29.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 18 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2 Nov 2026.
What to do
Upgrade vllm and vllm-project/vllm to 0.29.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| vllm-projectvllm | Affected
| Fixed in
|
GitHubvllm-project/vllmpkg:github/vllm-project/vllmOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to vllm version 0.29.0 or later, where this validation issue is fixed. No other mitigation is indicated. Patch status is confirmed by the versioning information.
Description
vLLM before 0.29.0 validates allowed_token_ids against tokenizer length instead of model output logits width in SamplingParams._validate_allowed_token_ids(). Attackers can supply token IDs above the output vocabulary that pass validation, causing LogitBiasState to corrupt GPU logits state and allow concurrent requests to sample tokens outside their allowlists.
References
- github.com/vllm-project/vllm/pull/49080 (opens in a new tab)
- github.com/vllm-project/vllm (opens in a new tab)
- github.com/vllm-project/vllm/commit/5b0e5b69ac1a3884a6479c9537789c95263cc804 (opens in a new tab)
- github.com/vllm-project/vllm/blob/v0.28.0/vllm/sampling_params.py (opens in a new tab)
- github.com/vllm-project/vllm/blob/v0.28.0/vllm/v1/worker/gpu/sample/logit_bias.py (opens in a new tab)
- vulncheck.com/advisories/vllm-before-0.29.0-cross-request-logits-corruption-via-allowed-token-ids (opens in a new tab)