PatchTheCVECVE-2026-100651: vLLM before 0.29.0 fails to enforce decoder prompt-length validation on the disaggregated serving endpoint /in
CVE-2026-100651 is a medium-severity flaw (CVSS 6.5) affecting vllm. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
vLLM before 0.29.0 fails to enforce decoder prompt-length validation on the disaggregated serving endpoint /inference/v1/generate. When the request contains a 'features' (multimodal) payload, vllm/entrypoints/serve/disagg/serving.py builds a multimodal EngineInput directly from the caller-supplied token_ids, and GenerateRequest.token_ids (vllm/entrypoints/serve/disagg/protocol.py) is not checked against model_config.max_model_len. For multimodal
Why this priority
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 6.5 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 68%) |
| CISA exploited list | No |
| Weakness | CWE-400 |
| 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-2026-100651?
vllm: upgrade to 0.29.0. Exact commands for each OS are on this page.
Is CVE-2026-100651 being exploited?
CVE-2026-100651 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-2026-100651 affect?
CVE-2026-100651 affects vllm. Severity is medium (CVSS 6.5). vLLM before 0.29.0 fails to enforce decoder prompt-length validation on the disaggregated serving endpoint /inference/v1/generate. When the request contains a 'features' (multimodal) payload, vllm/entrypoints/serve/disagg/serving.py builds
How urgent is CVE-2026-100651?
Priority 36/100. Public exploit reference
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