Is CVE-2026-116173 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-116173 being exploited in the wild.

How severe is CVE-2026-116173?

Medium severity, with a CVSS score of 5.9, published 25 October 2026.

Which products and versions are affected?

vllm (PyPI) ECOSYSTEM:introduced=0.22.0,fixed=0.24.0; vLLM Project vllm 0.22.0 to before 0.24.0.

How is CVE-2026-116173 attacked?

It is attacked over the network.

Am I affected by CVE-2026-116173?

Check whether you run vllm (PyPI) or vLLM Project vllm at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-116173: vLLM Rust gRPC denial of service via output_candidates validation bypass

CVE-2026-116173 · Severity: medium · CVSS 5.9 · Published 2026-10-25

vLLM is an open-source large language model inference engine that serves AI models over a network interface. Attackers can crash the inference engine by sending specially crafted requests that bypass input validation in the Rust gRPC frontend, causing a denial of service that takes the model offline and blocks all inference requests.

Technologies: vllm (PyPI), vLLM Project vllm. Vendors: PyPI, vLLM Project.

Quick answers

Is CVE-2026-116173 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-116173 being exploited in the wild.
How severe is CVE-2026-116173?: Medium severity, with a CVSS score of 5.9, published 25 October 2026.
Which products and versions are affected?: vllm (PyPI) ECOSYSTEM:introduced=0.22.0,fixed=0.24.0; vLLM Project vllm 0.22.0 to before 0.24.0.
Is there a fix for CVE-2026-116173?: Yes. vllm (PyPI): upgrade to 0.24.0 or later. Until then: Restrict network access to the Rust gRPC endpoint to trusted clients only, or run vLLM behind an API gateway that validates output_candidates.token_ids length before forwarding requests. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-116173 attacked?: It is attacked over the network.
Am I affected by CVE-2026-116173?: Check whether you run vllm (PyPI) or vLLM Project vllm at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

vllm (PyPI): upgrade to 0.24.0 or later
```
pip install "vllm>=0.24.0"
```

Restrict network access to the Rust gRPC endpoint to trusted clients only, or run vLLM behind an API gateway that validates output_candidates.token_ids length before forwarding requests.

Technical details

The Rust gRPC frontend accepts ResponseOptions.output_candidates.token_ids without enforcing the Python SamplingParams validator's 128-token limit (MAX_LOGPROB_TOKEN_IDS). Attackers send Generate or GenerateStream requests with output_logprobs enabled and over 128 token IDs, bypassing early validation and causing a fatal exception in the GPU logprob sampler when the oversized list reaches fixed-width tensor allocation. The vulnerability requires network access to the gRPC endpoint with no authentication required.

Affected products

vLLM Project vLLM 0.22.0 to before 0.24.0

Identifiers

CVE-2026-116173
GHSA-6pgw-f3pv-4h8q
PYSEC-2026-4350

Timeline

2026-10-09: disclosed
2026-10-25: advisory
2026-10-25: patched: vLLM 0.24.0 released

References

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