Improper input validation in Vllm
CVE-2026-54234
vLLM is a high-throughput and memory-efficient inference and serving engine for LLMs. Prior to 0.24.0, a frontend-legal multi-request speculative decoding workload can cause the rejection sampler to produce a recovered token equal to the model vocabulary size boundary value, which is then converted to negative one when the engine selects the next live token for a request and is written back into the drafter's input ids; that out-of-vocabulary value is later consumed by the model's embedding and attention path and crashes the engine worker with a GPU device-side assertion. The same triggering request sequence is reachable through the public gRPC Generate and Abort endpoints, so a remote client that can send generation requests can crash the shared engine worker, aborting concurrent requests and causing a service-wide denial of service for other clients of the deployment until the worker is restarted. This issue is fixed in version 0.24.0.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (47.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 47.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Vllm
- Vllm-Project Vllm — versions < 0.24.0
Weakness classification (CWE)
References
- github.com/vllm-project/vllm/security/advisories/GHSA-8wr5-jm2h-8r4f (Exploit, Vendor Advisory)
- github.com/vllm-project/vllm/pull/44744 (Patch, Issue Tracking)
- github.com/vllm-project/vllm/commit/8a5cf1ccd65e8ac7635c402c1ec0b08988bc26ca (Patch)
Frequently asked questions
- What is CVE-2026-54234?
- CVE-2026-54234 is a high-severity vulnerability in Vllm, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2026-07-06.
- How severe is CVE-2026-54234?
- High severity. CVSS v3 base score is 7.5 out of 10.