| Component | vLLM |
| Severity | medium (CVSS 5.3) |
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| Published (NVD) | 2026-09-26 |
| Last modified | 2026-10-06 |
| Affected versions | vllm < 0.29.0 |
| Fixed in | 0.29.0 |
| Weakness | CWE-20 |
| CISA KEV | not listed |
NVD 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.
What to do
- Upgrade vLLM to
0.29.0or later. - Do not expose the component's API or UI to the internet without authentication in front of it.
Sources
- NVD: CVE-2026-100647
- 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
Read more
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