CVE-2026-55514: vLLM is a library for LLM inference and serving

Routine

MEDIUM 6.5UPGRADE

CVE-2026-55514 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 is a library for LLM inference and serving. From 0.12.0 to before 0.24.0, sending a pure prompt embeds payload in a /v1/completions request with a model using M-RoPE causes EngineCore to fail an assertion and fatally crash, shutting down the entire server application. Any remote user who is authorized to make a /v1/completions request can make such a request and induce a crash. This issue is fixed in version 0.24.0.

Why this priority

No elevated risk signals yet

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	0.7% (top 49%)
CISA exploited list	No
Weakness	CWE-617
Published	2026-07-06
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: vllm

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-06 21:16 UTCPublished CVE record published
2026-10-25 20:10 UTCUpdated Record last modified

vllm vllm UPGRADE

Affected: >= 0.12.0 and < 0.24.0

Fixed in: 0.24.0

Safe to downgrade to: a release before 0.12.0

1. Check installed version

apt-cache policy vllm || rpm -q vllm || vllm --version

2. UPGRADE to 0.24.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade vllm

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade vllm

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 0.12.0 (Debian / Ubuntu)

apt-cache madison vllm sudo apt install vllm=<VERSION_BEFORE_0.12.0> sudo apt-mark hold vllm

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list vllm sudo dnf downgrade vllm-<VERSION_BEFORE_0.12.0> sudo dnf versionlock add vllm

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
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-2026-55514?

vllm: upgrade to 0.24.0. Exact commands for each OS are on this page.

Is CVE-2026-55514 being exploited?

CVE-2026-55514 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-2026-55514 affect?

CVE-2026-55514 affects vllm. Severity is medium (CVSS 6.5). vLLM is a library for LLM inference and serving. From 0.12.0 to before 0.24.0, sending a pure prompt embeds payload in a /v1/completions request with a model using M-RoPE causes EngineCore to fail an assertion and fatally crash, shutting do

How urgent is CVE-2026-55514?

Priority 36/100. No elevated risk signals yet.

Related CVEs

CVE-2026-54234 HIGH 7.5 UPGRADE vLLM is a high-throughput and memory-efficient inference and serving engine for LLMs
CVE-2026-55574 HIGH 7.5 UPGRADE vLLM is a high-throughput and memory-efficient inference and serving engine for LLMs
CVE-2026-55646 MEDIUM 6.5 UPGRADE vLLM is an inference and serving engine for large language models
CVE-2026-56340 HIGH 8.8 UPGRADE vLLM versions >= 0.10.2 and < 0.13.0 are missing sparse tensor validation in multimodal embeddings processing
CVE-2026-73560 MEDIUM 6.5 UPGRADE vLLM is an inference and serving engine for large language models

References

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