What’s Vulnerable › Vulnerabilities

CVE-2026-100647: vLLM before 0.29.0 CPU Exhaustion via unbounded cache_salt

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-26 · updated 2026-10-06
• Weakness: CWE-20

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.

Affected products

• vllm-project vllm: before 0.29.0 — fixed in 0.29.0

How to fix

Upgrade to a fixed version: vllm-project vllm 0.29.0. Check the vendor advisory for mitigations.

References

• https://github.com/vllm-project/vllm/security/advisories/GHSA-wpww-v874-ph2p
• https://www.vulncheck.com/advisories/vllm-before-0.29.0-cpu-exhaustion-via-unbounded-cache-salt

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