CVE-2026-54234

vLLM: Remote DoS in vLLM via Invalid Recovered Token Reinjection

HIGH
7.5
CVSS Score
Published: July 6, 2026 at 07:49 PM UTC
Updated: October 25, 2026 at 08:10 PM UTC
1 product affected across 1 vendorvLLM

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Severity
HIGH7.5
Exploit prediction
EPSS 0.6%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.24.0
Affected range stops below 0.24.0, so it looks safe — our inference, not a vendor statement

References (3)

x_refsource_CONFIRMVendor AdvisoryExploit
Source: cverecord
https://github.com/vllm-project/vllm/security/advisories/GHSA-8wr5-jm2h-8r4f
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/vllm-project/vllm/pull/44744

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-20CWE-1284

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