---
title: "CVE-2025-47277: vLLM Allows Remote Code Execution via PyNcclPipe Communication Service"
url: https://erroneo.us/security/cve/CVE-2025-47277/
description: "CVE-2025-47277 (vllm (PyPI)): 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…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-05-20
date_modified: 2026-07-17
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-47277"
kev: false
cvss: 9.8
epss: 0.00964
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-47277: vLLM Allows Remote Code Execution via PyNcclPipe Communication Service

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 1.0% , percentile 61: FIRST’s model estimates a 1.0% chance of exploitation activity in the next 30 days, higher than 61% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes vllm (PyPI) >= 0.6.5, < 0.8.5, fixed in 0.8.5 . Check your lockfile, including transitive dependencies.

## What it is

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 sendobj and recvobj 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.

## Affected packages

- PyPI `vllm` >= 0.6.5, < 0.8.5 → fixed: 0.8.5

## Affected products (CVE record)

- vllm-project vllm: >= 0.6.5, < 0.8.5

## Severity

- GitHub_M CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.96% probability of exploitation activity in the next 30 days; percentile 61.

## Sources

- [GitHub Advisory GHSA-hjq4-87xh-g4fv](https://github.com/advisories/GHSA-hjq4-87xh-g4fv)
- [CVE.org record CVE-2025-47277](https://www.cve.org/CVERecord?id=CVE-2025-47277)
- [NVD entry CVE-2025-47277](https://nvd.nist.gov/vuln/detail/CVE-2025-47277)
- [github.com](https://github.com/vllm-project/vllm/security/advisories/GHSA-hjq4-87xh-g4fv)
- [github.com](https://github.com/vllm-project/vllm/pull/15988)
- [github.com](https://github.com/vllm-project/vllm/commit/0d6e187e88874c39cda7409cf673f9e6546893e7)
- [docs.vllm.ai](https://docs.vllm.ai/en/latest/deployment/security.html)
- [github.com](https://github.com/pypa/advisory-database/tree/main/vulns/vllm/PYSEC-2026-567.yaml)
- [github.com](https://github.com/vllm-project/vllm)
- [pypi.org](https://pypi.org/project/vllm)

---
Source page: https://erroneo.us/security/cve/CVE-2025-47277/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt