gcdRadar
archive/Patch now/AIR-2025-0292
closedclosed 28 May 2025Patch now2 Disclosed vulnerabilityAI

CVE-2025-48943: vLLM Denial of Service via Invalid Regex Output

vLLM

Providing an invalid regular expression during structured output generation causes the vLLM server to crash. This creates a denial of service vulnerability for API clients.

disclosed CVENo confirmed exploitation, so this record is tracked as a disclosed vulnerability and not counted as an incident. It moves into the counts if CISA or the vendor confirms exploitation. Why

CVSS
6.5
EPSS
0.01 · top 57% · 2026-11-13
EPSS scores by FIRST
fix status
Fix status unknown
first report
28 May 2025
last update
30 May 2025
CVE ids
CVE-2025-48943other records

Timeline · 2

  1. 28 May 2025CVE-2025-48943: vLLM allows clients to crash the openai server with invalid regex
  2. 30 May 2025CVE-2025-48943: vLLM is an inference and serving engine for large language models (LLMs).

Sources · 2

Advisories and databases

  1. 2025-05-28
    CVE-2025-48943: vLLM allows clients to crash the openai server with invalid regex
    GitHub Advisory Database · github.com/advisories/GHSA-9hcf-v7m4-6m2j
  2. 2025-05-30
    CVE-2025-48943: vLLM is an inference and serving engine for large language models (LLMs).
    NVD · nvd.nist.gov/vuln/detail/CVE-2025-48943

Titles and links belong to their publishers. The summary above is written by gcdRadar in its own words; data is CC BY-SA 4.0.

Classification

lane
Patch now
AI role
Attack on AI
categories
Infrastructure vulnerability
severity
2 · Disclosed vulnerability
fix status
Fix status unknown
targets
Framework / tooling
owasp llm top 10
LLM03:2025 Supply Chain
mitre atlas
no technique for these categories
tags
vllmdos
dates
happened 28 May 2025 · first reported 28 May 2025
origin
GitHub Advisory Database
Vulnerability record from NVD / the GitHub Advisory Database. This product uses the NVD API but is not endorsed or certified by the NVD.
record
confidence 0.95 · created 2026-10-18 07:00Z · updated 2026-10-18 10:04Z

Lane, AI role, categories and severity come from the classifier; the OWASP and ATLAS rows are derived from the categories. How these are assigned

Copy a brief

This record as a short Markdown brief, for a ticket, a chat or a coding agent.

the brief as text
# CVE-2025-48943: vLLM Denial of Service via Invalid Regex Output

https://gcdradar.vercel.app/incidents/cve-2025-48943-vllm-denial-of-service-via-invalid-regex-outp · AIR-2025-0292 · closed 2025-05-28

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability)
- Fix status: Fix status unknown
- First reported: 2025-05-28
- AI role: Attack on AI
- Products: vLLM
- CVE ids: CVE-2025-48943
- CVSS: 6.5

## Summary

Providing an invalid regular expression during structured output generation causes the vLLM server to crash. This creates a denial of service vulnerability for API clients.

## What to do

No action recorded; read the sources below and the vendor's advisory.

## Latest updates

- 2025-05-30: CVE-2025-48943: vLLM is an inference and serving engine for large language models (LLMs). (https://nvd.nist.gov/vuln/detail/CVE-2025-48943)
- 2025-05-28: CVE-2025-48943: vLLM allows clients to crash the openai server with invalid regex (https://github.com/advisories/GHSA-9hcf-v7m4-6m2j)

## Sources

- 2025-05-28 GitHub Advisory Database: CVE-2025-48943: vLLM allows clients to crash the openai server with invalid regex https://github.com/advisories/GHSA-9hcf-v7m4-6m2j
- 2025-05-30 NVD: CVE-2025-48943: vLLM is an inference and serving engine for large language models (LLMs). https://nvd.nist.gov/vuln/detail/CVE-2025-48943

Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.

Related

  1. closed6.5
    vLLM CVE-2025-48942: vLLM Denial of Service via Invalid JSON Schema

    Patch now · Disclosed · since 28 May 2025 · updated 30 May 2025 · CVE-2025-48942

    AI
  2. closed6.5
    vLLM CVE-2025-48887: vLLM ReDoS Vulnerability in pythonic_tool_parser

    Patch now · Disclosed · since 28 May 2025 · updated 30 May 2025 · CVE-2025-48887

    AI
  3. closed
    vLLM vLLM Regular Expression Denial of Service

    Patch now · Disclosed · since 28 May 2025

    AI
  4. closed4.2
    vLLM CVE-2025-46722: vLLM MultiModalHasher Image Hashing Weakness

    Patch now · Disclosed · since 28 May 2025 · updated 29 May 2025 · CVE-2025-46722

    AI
  5. closed2.6
    vLLM CVE-2025-46570: Timing Side-Channel in vLLM Prefix Caching

    Patch now · Disclosed · since 28 May 2025 · updated 29 May 2025 · CVE-2025-46570

    AI
  6. closed6.5
    vLLM CVE-2025-48944: vLLM Tool Schema Allows DoS via Malformed Fields

    Patch now · Disclosed · since 28 May 2025 · updated 30 May 2025 · CVE-2025-48944

    AI