CVE-2026-100647

vLLM before 0.29.0 CPU Exhaustion via unbounded cache_salt

State
Published
Severity
6.9 Medium
Published
Sep 26, 2026
Updated
Sep 28, 2026
Reserved
Sep 26, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
4.06.9 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NVulnCheck
3.15.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LVulnCheck

Weaknesses

  • CWE-20 Improper Input Validation

Affected Products

ProductVersions
vllmvllm-project
  • before 0.29.0Affected
  • 0.29.0Not affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.