CVE-2026-54234: Vllm vulnerability (CVSS 7.5)

Description

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

Vllm< 0.24.0

Remediation

Fixed in

Vllm≥ 0.24.0

Patch & vendor advisories

References

https://github.com/vllm-project/vllm/commit/8a5cf1ccd65e8ac7635c402c1ec0b08988bc26caPatch
https://github.com/vllm-project/vllm/pull/44744Issue TrackingPatch
https://github.com/vllm-project/vllm/security/advisories/GHSA-8wr5-jm2h-8r4fVendor AdvisoryExploit

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-54234 being actively exploited?

CVE-2026-54234 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.62%.

How severe is CVE-2026-54234?

CVE-2026-54234 has a CVSS 3.1 base score of 7.5, rated high. EPSS estimates a 0.62% probability of exploitation.

Which products are affected by CVE-2026-54234?

Affected products include Vllm.

How do I fix CVE-2026-54234?

Upgrade affected software to a fixed version, for example Vllm 0.24.0 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-54234 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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