CVE-2026-93989 vLLM through 0.29.0 Cross-Request Logits Corruption via bad_words
Attackers can corrupt logits memory of concurrent requests by supplying out-of-bounds token indices, causing incorrect token generation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-93989?
CVE-2026-93989 is a low-severity memory corruption vulnerability in Vllm Vllm, published on 19 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
vLLM through 0.29.0 fails to properly validate bad_words token indices against the model's generation output width in SamplingParams.update_from_tokenizer(). Attackers can supply out-of-bounds token indices that corrupt logits memory of concurrent requests, causing different in-flight HTTP requests to return incorrect tokens.
Weakness: CWE-129
Which versions are affected by CVE-2026-93989?
1 open source package ship an affected version, including vllm. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
vllm PyPI | All versions | 0.30.0 |
Products include Vllm Vllm.
How do I fix CVE-2026-93989?
Upgrade vllm to 0.30.0 or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-93989 being exploited?
There is no known exploitation of CVE-2026-93989 in the wild and no public exploit code.
Other vulnerabilities in Vllm Vllm
- CVE-2025-32444 vLLM Vulnerable to Remote Code Execution via Mooncake Integration
- CVE-2026-22778 vLLM leaks a heap address when PIL throws an error
- CVE-2025-47277 vLLM Allows Remote Code Execution via PyNcclPipe Communication Service
- CVE-2024-11041 Remote Code Execution in vllm-project/vllm
- CVE-2026-48746 vLLM: OpenAI auth bypass
Sources
Also known as GHSA-pc5q-2x89-w436, MINI-hjj4-jr5g-8cmw, MINI-m2jx-j68h-jmxf, MINI-qchg-gg2q-q534, PYSEC-2026-4000.