CVE-2025-48942: vLLM DOS Remotely Kill Vllm Over Http Vulnerability

Q: What is CVE-2025-48942?

CVE-2025-48942 is a security vulnerability in vLLM DOS involving Remotely kill vllm over http with invalid JSON schema under CWE-248: Uncaught Exception.

Q: Which vLLM DOS versions are affected?

Affected versions include releases prior to 0.9.0 across affected packages: vllm.

Q: What version fixes CVE-2025-48942?

Upgrading to 0.9.0 (or the latest patched release for your respective branch) resolves the vulnerability.

Q: Is vllm affected?

Yes, vllm is affected in releases prior to 0.9.0. Upgrade your dependency to 0.9.0 or later.

Q: What is the CVSS score of CVE-2025-48942?

CVE-2025-48942 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Q: What CWE is associated with CVE-2025-48942?

CVE-2025-48942 is classified under CWE-248: Uncaught Exception (An exception is thrown from a function, but it is not caught.).

Q: How can I check PyPI dependencies for CVE-2025-48942?

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.

MODERATE

Advisory Identifier: GHSA-6qc9-v4r8-22xg

CVSS 6.5

CWE-248

Published 2025-05-28

Advisory Summary

CVE-2025-48942 is a MODERATE (CVSS 6.5) remotely kill vllm over http vulnerability (CWE-248: Uncaught Exception) affecting vLLM DOS libraries in the PyPI ecosystem. The issue involves remotely kill vllm over http with invalid json schema. Remediation is available by upgrading affected packages to version 0.9.0.

CVE-2025-48942 at a Glance

CVE Identifier CVE-2025-48942

GHSA Identifier GHSA-6qc9-v4r8-22xg

Severity MODERATE

CVSS v3.1 Base Score 6.5

CWE Classification CWE-248: Uncaught Exception

Affected Product vLLM DOS

Package Ecosystem PyPI

Published Date 2025-05-28

Last Updated 2025-06-27

Security Impact

CVSS: 6.5

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

Attack Vector Network (AV:N)

Attack Complexity Low (AC:L)

Privileges Required Low (PR:L)

User Interaction None (UI:N)

Scope Unchanged (S:U)

Confidentiality None (C:N)

Integrity None (I:N)

Availability High (A:H)

How to Fix CVE-2025-48942

To remediate this vulnerability, upgrade all affected vLLM DOS 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: 0.9.0

pip install vllm>=0.9.0

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-2025-48942, inspect your installed packages using pip:

pip show vllm

Analyze the terminal output to locate any version of vLLM DOS in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.9.0), 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-248: Uncaught Exception, where an exception is thrown from a function, but it is not caught. In vLLM DOS, 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

### 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

CVE-2025-48942 Affected vLLM DOS Versions

1 component(s)

Fixed Versions:

0.9.0

Product / Package	Ecosystem	Affected Versions	Fixed Version
vllm pypi/vllm	PyPI	≥ 0.8.0 < 0.9.0	0.9.0

References

GitHub Advisory / Wiki ADVISORY

https://github.com/vllm-project/vllm/security/advisories/GHSA-6qc9-v4r8-22xg

NVD — CVE-2025-48942 NVD

https://nvd.nist.gov/vuln/detail/CVE-2025-48942

vLLM DOS Source Repository REPOSITORY

https://github.com/vllm-project/vllm/issues/17248

vLLM DOS Source Repository REPOSITORY

https://github.com/vllm-project/vllm/pull/17623

Security Fix Commit FIX COMMIT

https://github.com/vllm-project/vllm/commit/08bf7840780980c7568c573c70a6a8db94fd45ff

vLLM DOS Source Repository REPOSITORY

https://github.com/pypa/advisory-database/tree/main/vulns/vllm/PYSEC-2025-54.yaml

vLLM DOS Source Repository REPOSITORY

https://github.com/vllm-project/vllm

Frequently Asked Questions

What is CVE-2025-48942?

CVE-2025-48942 is a security vulnerability in vLLM DOS involving Remotely kill vllm over http with invalid JSON schema under CWE-248: Uncaught Exception.

Which vLLM DOS versions are affected?

Affected versions include releases prior to 0.9.0 across affected packages: vllm.

What version fixes CVE-2025-48942?

Upgrading to 0.9.0 (or the latest patched release for your respective branch) resolves the vulnerability.

Is vllm affected?

Yes, vllm is affected in releases prior to 0.9.0. Upgrade your dependency to 0.9.0 or later.

What is the CVSS score of CVE-2025-48942?

CVE-2025-48942 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

What CWE is associated with CVE-2025-48942?

CVE-2025-48942 is classified under CWE-248: Uncaught Exception (An exception is thrown from a function, but it is not caught.).

How can I check PyPI dependencies for CVE-2025-48942?

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

View Raw JSON

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-6qc9-v4r8-22xg",
  "modified" : "2025-06-27T21:06:56Z",
  "published" : "2025-05-28T19:41:53Z",
  "aliases" : [ "CVE-2025-48942" ],
  "summary" : "vLLM DOS: Remotely kill vllm over http with invalid JSON schema",
  "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 '{\"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\\\"}}}\"}'   \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 '{\"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\\\"}}}\"}'\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<picojson::object>()) 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",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "vllm"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.8.0"
      }, {
        "fixed" : "0.9.0"
      } ]
    } ]
  } ],
  "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"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-248" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-05-28T19:41:53Z",
    "nvd_published_at" : "2025-05-30T19:15:30Z"
  }
}

CVSS V3

6.5 MODERATE

Attack Vector Network (AV:N)

Attack Complexity Low (AC:L)

Privileges Required Low (PR:L)

User Interaction None (UI:N)

Scope Unchanged (S:U)

Confidentiality None (C:N)

Integrity None (I:N)

Availability High (A:H)

Vector String

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Advisory Metadata

Source ID: GHSA-6qc9-v4r8-22xg
Schema Version: 1.4.0
Published: 2025-05-28 19:41
Last Modified: 2025-06-27 21:06
Database Record File: advisories/github-reviewed/2025/05/GHSA-6qc9-v4r8-22xg/GHSA-6qc9-v4r8-22xg.json