criticalCVSS 9.8NVD status: Analyzed

CVE-2025-47277

vLLM, an inference and serving engine for large language models (LLMs), has an issue in versions 0.6.5 through 0.8.4 that ONLY impacts environments using the `PyNcclPipe` KV cache transfer integration with the V0 engine.

ComponentvLLM
Severitycritical (CVSS 9.8)
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published (NVD)2025-05-20
Last modified2026-06-17
Affected versions
vllm >= 0.6.5, < 0.8.5
Fixed in0.8.5
WeaknessCWE-502
CISA KEVnot listed

NVD description

vLLM, an inference and serving engine for large language models (LLMs), has an issue in versions 0.6.5 through 0.8.4 that ONLY impacts environments using the `PyNcclPipe` KV cache transfer integration with the V0 engine. No other configurations are affected. vLLM supports the use of the `PyNcclPipe` class to establish a peer-to-peer communication domain for data transmission between distributed nodes. The GPU-side KV-Cache transmission is implemented through the `PyNcclCommunicator` class, while CPU-side control message passing is handled via the `send_obj` and `recv_obj` methods on the CPU side.​ The intention was that this interface should only be exposed to a private network using the IP address specified by the `--kv-ip` CLI parameter. The vLLM documentation covers how this must be limited to a secured network. The default and intentional behavior from PyTorch is that the `TCPStore` interface listens on ALL interfaces, regardless of what IP address is provided. The IP address given was only used as a client-side address to use. vLLM was fixed to use a workaround to force the `TCPStore` instance to bind its socket to a specified private interface. As of version 0.8.5, vLLM limits the `TCPStore` socket to the private interface as configured.

Does CVE-2025-47277 hit the version you run?Paste your docker-compose.yml, requirements.txt or package.json. The scanner checks your pinned versions against this CVE and every other one we track for vLLM.
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What to do

  • Upgrade vLLM to 0.8.5 or later.
  • Do not expose the component's API or UI to the internet without authentication in front of it.

Sources

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