vllm-project vLLM up to 0.26.x Activation Kernels activation_kernels.cu act_and_mul_kernel integer overflow

Summaryinfo

A vulnerability, which was classified as problematic, has been found in vllm-project vLLM up to 0.26.x. The impacted element is the function act_and_mul_kernel of the file activation_kernels.cu of the component Activation Kernels. Performing a manipulation results in integer overflow. This vulnerability is cataloged as CVE-2026-73558. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in vllm-project vLLM up to 0.26.x. This affects the function act_and_mul_kernel of the file activation_kernels.cu of the component Activation Kernels. The manipulation with an unknown input leads to a integer overflow vulnerability. CWE is classifying the issue as CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. This is going to have an impact on confidentiality. The summary by CVE is:

vLLM is an inference and serving engine for large language models. Prior to 0.27.0, an integer overflow in blockIdx.x * 2 * d in activation_kernels.cu can cause act_and_mul_kernel to consume another batched user's input, allowing a request processed in the same inference batch to receive a partial or complete copy of another user's inference result. This issue is fixed in version 0.27.0.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-73558 since 08/12/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available.

Upgrading to version 0.27.0 eliminates this vulnerability.

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Productinfo

Type

• Project Management Software

Vendor

• vllm-project

Name

• vLLM

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26

Website

• Product: https://github.com/vllm-project/vllm/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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