CVE-2026-100647

MEDIUM 5.3

vLLM before 0.29.0 CPU Exhaustion via unbounded cache_salt

CVSS Score

5.3

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-20
Vendor	vllm-project
Product	vllm
Published	Sep 26, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Affected Versions

vllm-project / vllm

0 < 0.29.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

🔍 wildoranges jperezdealgaba