# CVE-2026-93841: vLLM through 0.29.0 Adjacent-Request Sampler State Corruption via Unvalidated Prompt Token IDs

> Attackers can corrupt concurrent request sampler states via out-of-bounds writes in vLLM's Triton kernel, altering model output behavior.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-q9hm-g73w-q6wp, MINI-p796-rv9r-rgqj, MINI-r47v-q555-v6cw, MINI-rjr5-qrmp-jqgv, PYSEC-2026-3999

## What is CVE-2026-93841?

CVE-2026-93841 is a medium-severity memory corruption vulnerability in Vllm Vllm, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

vLLM through 0.29.0 contains a memory corruption vulnerability in the Triton _bincount_kernel where prompt token IDs index the penalty prompt-presence bitset without bounds checking against vocabulary size. Attackers can submit multimodal audio requests with tokens equal to vocabulary size, causing out-of-bounds writes that corrupt concurrent requests' sampler state and alter repetition penalty behavior.

Weakness: CWE-129 (Improper Validation of Array Index)

## Which versions are affected by CVE-2026-93841?

1 open source package ship an affected version, including vllm. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `vllm` | PyPI | All versions | 0.30.0 |

Products: Vllm Vllm.

## How do I fix CVE-2026-93841?

Upgrade vllm to 0.30.0 or later.

## Is CVE-2026-93841 being exploited?

There is no known exploitation of CVE-2026-93841 in the wild and no public exploit code.

## Other vulnerabilities in Vllm Vllm

- [CVE-2025-32444](https://insights.sbomify.com/CVE-2025-32444/): vLLM Vulnerable to Remote Code Execution via Mooncake Integration (critical 10.0)
- [CVE-2026-22778](https://insights.sbomify.com/CVE-2026-22778/): vLLM leaks a heap address when PIL throws an error (critical 9.8)
- [CVE-2025-47277](https://insights.sbomify.com/CVE-2025-47277/): vLLM Allows Remote Code Execution via PyNcclPipe Communication Service (critical 9.8)
- [CVE-2024-11041](https://insights.sbomify.com/CVE-2024-11041/): Remote Code Execution in vllm-project/vllm (critical 9.8)
- [CVE-2026-48746](https://insights.sbomify.com/CVE-2026-48746/): vLLM: OpenAI auth bypass (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93841 and fix it if it is affected.

What it is: CVE-2026-93841 is a medium-severity memory corruption vulnerability in Vllm Vllm, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-93841 in the wild and no public exploit code.

Affected packages and fixed versions:
- vllm (PyPI): affected all versions; fixed in 0.30.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-93841/ (Markdown: https://insights.sbomify.com/CVE-2026-93841/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93841
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93841
- OSV: https://osv.dev/vulnerability/CVE-2026-93841

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93841/
Summaries are generated and may contain mistakes; the official description above is the record.