Description
vLLM versions before 0.29.0 contain a denial-of-service vulnerability in the cache_salt parameter accepted on OpenAI-compatible and Anthropic API endpoints, which lacks maximum length validation and is processed on the single EngineCore scheduler thread. Unauthenticated attackers can send HTTP requests with multi-hundred-megabyte salt values that trigger expensive pickle serialization and SHA-256 hashing, stalling the scheduler thread and denying service to all concurrent requests.
Published: 2026-09-26
Score: 6.9 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Sun, 27 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1322
References
Metrics threat_severity

None

threat_severity

Moderate


Sat, 26 Sep 2026 13:30:00 +0000

Type Values Removed Values Added
Description vLLM versions before 0.29.0 contain a denial-of-service vulnerability in the cache_salt parameter accepted on OpenAI-compatible and Anthropic API endpoints, which lacks maximum length validation and is processed on the single EngineCore scheduler thread. Unauthenticated attackers can send HTTP requests with multi-hundred-megabyte salt values that trigger expensive pickle serialization and SHA-256 hashing, stalling the scheduler thread and denying service to all concurrent requests.
Title vLLM before 0.29.0 CPU Exhaustion via unbounded cache_salt
First Time appeared Vllm
Vllm vllm
Weaknesses CWE-20
CPEs cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:*
Vendors & Products Vllm
Vllm vllm
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-26T13:23:18.240Z

Reserved: 2026-09-26T02:33:07.898Z

Link: CVE-2026-100647

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-26T14:16:47.097

Modified: 2026-09-26T14:16:47.097

Link: CVE-2026-100647

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-26T13:23:18Z

Links: CVE-2026-100647 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-27T02:00:18Z

Weaknesses
  • CWE-1322

    Use of Blocking Code in Single-threaded, Non-blocking Context

  • CWE-20

    Improper Input Validation