PatchTheCVECVE-2026-100647: vLLM versions before 0.29.0 contain a denial-of-service vulnerability in the cache_salt parameter accepted on
CVE-2026-100647 is a medium-severity flaw (CVSS 5.3) affecting vllm. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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
Why this priority
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.3 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 72%) |
| CISA exploited list | No |
| Weakness | CWE-20 |
| Published | 2026-09-26 |
| Last modified | 2026-10-06 |
Last updated 2026-10-06 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-100647?
vllm: upgrade to 0.29.0. Exact commands for each OS are on this page.
Is CVE-2026-100647 being exploited?
CVE-2026-100647 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-100647 affect?
CVE-2026-100647 affects vllm. Severity is medium (CVSS 5.3). 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 sch
How urgent is CVE-2026-100647?
Priority 31/100. Remotely exploitable, no login, no user action
Software pages
OpenAI and LLM tools vulnerabilities
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