CVE-2026-93989Network attack vectorHinoki check available

Cross-request output corruption via out-of-bounds token indices

Published Sep 19, 2026 · Updated Sep 19, 2026

Improper token-index validation in vLLM 0.29.0 and earlier allows remote authenticated users to corrupt concurrent request output. SamplingParams.update_from_tokenizer() checks bad_words IDs against the tokenizer vocabulary rather than the model logits width, enabling out-of-bounds BadWords Triton kernel writes. Exploitation requires crafted token IDs and concurrent inference requests; the documented consequence is incorrect generated tokens in other HTTP responses.

CVSS severity2.3
Low
EPSS probability0.20%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper token-index validation in vLLM 0.29.0 and earlier allows remote authenticated users to corrupt concurrent request output. SamplingParams.update_from_tokenizer() checks bad_words IDs against the tokenizer vocabulary rather than the model logits width, enabling out-of-bounds BadWords Triton kernel writes. Exploitation requires crafted token IDs and concurrent inference requests; the documented consequence is incorrect generated tokens in other HTTP responses.

The record

CVE
CVE-2026-93989
Published
Sep 19, 2026
Updated
Sep 19, 2026
Vendor
vLLM Project
Product
vLLM
Classifications
CWE-129, T1565.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=0.29.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

vLLM Project · vLLMversion=0 <=0.29.0

Published CVSS scores

3.1VulnCheck CNACVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
2.3VulnCheck CNACVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-129Improper Validation of Array Index
T1565.003Runtime Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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