CVE-2026-53923 PUBLISHED

vLLM GGUF Kernels: int64_t to int truncation of tensor dimensions causes GPU buffer overflow

Assigner: GitHub_M
Reserved: 11.06.2026 Published: 22.06.2026 Updated: 23.06.2026

vLLM is an inference and serving engine for large language models (LLMs). From 0.5.5 until 0.23.1rc0, integer truncation of tensor dimensions in vLLM's GGUF dequantize kernels (csrc/quantization/gguf/gguf_kernel.cu) causes partial tensor processing. The output tensor is allocated at full size via torch::empty (uninitialized memory), but the dequantize CUDA kernel processes only a truncated number of elements. The unfilled portion of the output tensor retains whatever was previously in GPU memory. In multi-tenant inference deployments, this residual GPU memory may contain tensor data from other users' inference requests, constituting information disclosure. This vulnerability is fixed in 0.23.1rc0.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
CVSS Score: 5.3

Product Status

Vendor vllm-project
Product vllm
Versions
  • Version >= 0.5.5, < 0.23.1rc0 is affected

References

Problem Types

  • CWE-681: Incorrect Conversion between Numeric Types CWE
  • CWE-200: Exposure of Sensitive Information to an Unauthorized Actor CWE