Is CVE-2026-115916 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-115916 being exploited in the wild.

How severe is CVE-2026-115916?

Medium severity, with a CVSS score of 6.5, published 26 October 2026.

Which products and versions are affected?

vllm (PyPI) < 0.32.0, ECOSYSTEM:introduced=0,fixed=0.32.0; vLLM Project vllm before 0.32.0.

Is there a fix for CVE-2026-115916?

Yes. vllm (PyPI): upgrade to 0.32.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-115916 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-115916?

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-2026-115916: vLLM off-by-one error in tokenizer max_token_id validation

Q: Which products and versions are affected?

vllm (PyPI) < 0.32.0, ECOSYSTEM:introduced=0,fixed=0.32.0; vLLM Project vllm before 0.32.0.

Q: Is there a fix for CVE-2026-115916?

Yes. vllm (PyPI): upgrade to 0.32.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-115916 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-115916?

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-2026-115916 · Severity: medium · CVSS 6.5 · Published 2026-10-26

vLLM is an inference engine for large language models used to run LLM-based services. Prior to version 0.32.0, a tokenizer validation bug allows an attacker to submit a specially crafted input token ID that bypasses validation and causes the CUDA GPU to crash with an assertion error, terminating the service and causing denial of service.

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

Quick answers

Is CVE-2026-115916 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-115916 being exploited in the wild.
How severe is CVE-2026-115916?: Medium severity, with a CVSS score of 6.5, published 26 October 2026.
Which products and versions are affected?: vllm (PyPI) < 0.32.0, ECOSYSTEM:introduced=0,fixed=0.32.0; vLLM Project vllm before 0.32.0.
Is there a fix for CVE-2026-115916?: Yes. vllm (PyPI): upgrade to 0.32.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-115916 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-115916?: 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 0.32.0 or later
```
pip install "vllm>=0.32.0"
```

Technical details

The vllm/tokenizers/hf.py module computes max_token_id as vocab_size instead of vocab_size - 1, allowing a pre-tokenized prompt ID equal to vocabulary size to pass validation. When tensor parallelism is 1 and vocabulary size is an exact multiple of 64, VocabParallelEmbedding.forward fails to mask this out-of-bounds index before calling F.embedding, triggering a CUDA device-side assertion that terminates the engine.

Affected products

vLLM Project vLLM before 0.32.0

Identifiers

CVE-2026-115916
GHSA-q97c-p368-75c4
PYSEC-2026-4347

Timeline

2026-10-26: disclosed
2026-10-01: patched: fix merged to main branch

References

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