CVE-2026-100647
Vllm: improper input validation
- Risk score
- 56/100
- CVSS
- 7.5 v3.1
- Exploit chance (30 days)
- 0.3%
- Published
- 26 Sep 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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-hund…
- Affected
- Vllm before 0.29.0
- Fix
- Upgrade Vllm to 0.29.0 or later.
- Exploitation
- No known exploitation
Story map
At a glance
Vllm: Amber, patch this week. vLLM versions 0.22.0 through 0.23.0 fail to validate stop_token_ids against vocabulary bounds in Rust HTTP and gRPC frontends, allowing out-of-vocabulary token IDs to reach MinTokensLogitsProcessor. Attackers can submit requests with min_tokens greater than zero and out-of-vocabulary stop_token_ids to trigger CUDA ten…
The flaws
- CVE-2026-100647: Improper input validation (CVSS 7.5 · EPSS 0%)
- CVE-2026-100652: Improper input validation (CVSS 7.5 · EPSS 0%)
- CVE-2026-105759: VLLM is an inference and serving engine for large language models (CVSS 7.5 · EPSS 0%)
- CVE-2026-103241: Denial of service (CVSS 7.5 · EPSS 1%)
The fix
Upgrade Vllm: 0.29.0 · 0.30.0 or later on your release line
Who is exposed: Vllm
Where it stands
- Public proof of concept
Connects to
- Same weakness: Denial of service (CWE-400). 253 other warnings in 30 days
- Same product: Earlier Vllm warnings. 15 in the last 90 days
Why it is Yellow
- CVSS 7.5 high
- Remotely exploitable without logging in
References
Original 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.
Last activity 26 Sep 2026. Patch Forecast updates every hour.