CVE-2024-8939

Service interruption via unbounded best_of processing

Published Sep 17, 2024 · Updated Nov 20, 2025

Resource exhaustion in vLLM before 0.5.0.post1 and RHEL AI allows attackers to make the JSON completion API unresponsive. The completion handler accepts best_of as the number of candidate generations without an effective bound or timeout, so a large value consumes excessive processing resources. Exposure beyond localhost is required, and exhaustion interrupts API service without reported data disclosure or modification.

CVSS severity6.2
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in vLLM before 0.5.0.post1 and RHEL AI allows attackers to make the JSON completion API unresponsive. The completion handler accepts best_of as the number of candidate generations without an effective bound or timeout, so a large value consumes excessive processing resources. Exposure beyond localhost is required, and exhaustion interrupts API service without reported data disclosure or modification.

The record

CVE
CVE-2024-8939
Published
Sep 17, 2024
Updated
Nov 20, 2025
Vendor
vLLM Project
Product
vLLM
Classifications
CWE-400, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 17, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 20, 2025Record 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 <0.5.0.post1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

vLLM Project · vLLMversion=0 <0.5.0.post1
389 Directory Server · Red Hat Enterprise Linux AIAffected versions are unavailable in this record.

Published CVSS scores

6.9GitHubCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
6.2Red HatCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

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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