CVE-2026-34237

MEDIUM EPSS 12.7%
Published Mar 31, 20263mo ago · Modified Jun 17, 20261w ago
6.1 CVSS 3.1
Medium
Find Similar
Published Mar 31, 2026 3mo ago
Last Modified Jun 17, 2026 1w ago

Description

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.

CVSS Details

Base Score
6.1
Exploitability
2.8
Impact
2.7
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction Required
Scope Changed
Confidentiality Low
Integrity Low
Availability None

Threat Intelligence

EPSS Exploit Probability
12.7% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-942

Affected Products 2

VendorProductVersionRange
lfprojectsmcp_java_sdk* <1.0.1
lfprojectsmcp_java_sdk1.1.0any

References 3

  • github.com https://github.com/modelcontextprotocol/java-sdk/blob/main/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletSseServerTransportProvider.java#L289
    Patch
  • github.com https://github.com/modelcontextprotocol/java-sdk/blob/main/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletStreamableServerTransportProvider.java#L525
    Patch
  • github.com https://github.com/modelcontextprotocol/java-sdk/security/advisories/GHSA-hv2w-8mjj-jw22
    MitigationVendor Advisory

Remediation

  • github.com https://github.com/modelcontextprotocol/java-sdk/blob/main/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletSseServerTransportProvider.java#L289
    Patch
  • github.com https://github.com/modelcontextprotocol/java-sdk/blob/main/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletStreamableServerTransportProvider.java#L525
    Patch