---
id: CVE-2026-34237
title: >-
  MCP Java SDK is the official Java SDK for Model Context Protocol servers and
  clients
summary: >-
  MCP Java SDK is the official Java SDK for Model Context Protocol servers and
  clients. Prior to versions 0.83.0, 1.0.1, and 1.1.1, there is a hardcoded
  wildcard CORS vulnerability. This issue has been patched in versions 0.83.0,
  1.0.1, an…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-942
vendor: lfprojects
product: mcp_java_sdk
affected:
  - mcp_java_sdk < 1.0.1
  - mcp_java_sdk = 1.1.0
patched:
  - mcp_java_sdk 1.0.1
published: '2026-03-31'
updated: '2026-07-24'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-34237'
references:
  - url: >-
      https://github.com/modelcontextprotocol/java-sdk/blob/main/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletSseServerTransportProvider.java#L289
    label: security-advisories@github.com
  - url: >-
      https://github.com/modelcontextprotocol/java-sdk/blob/main/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletStreamableServerTransportProvider.java#L525
    label: security-advisories@github.com
  - url: >-
      https://github.com/modelcontextprotocol/java-sdk/security/advisories/GHSA-hv2w-8mjj-jw22
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.0031
epssPercentile: 0.21246
ingestedAt: '2026-07-24T20:38:02.469Z'
---

## Overview

MCP Java SDK is the official Java SDK for Model Context Protocol servers and clients. Prior to versions 0.83.0, 1.0.1, and 1.1.1, there is a hardcoded wildcard CORS vulnerability. This issue has been patched in versions 0.83.0, 1.0.1, and 1.1.1.

## Affected

- `mcp_java_sdk < 1.0.1`
- `mcp_java_sdk = 1.1.0`

## Remediation

Upgrade past the affected range:

- `mcp_java_sdk 1.0.1`