CVE-2026-34237
Published:March 31, 2026
Updated:April 23, 2026
MCP Java SDK is the official Java SDK for Model Context Protocol servers and clients. Prior to versions 1.0.1 and 1.1.1, there is a hardcoded wildcard CORS vulnerability. This issue has been patched in versions 1.0.1 and 1.1.1.
Affected Packages
https://github.com/modelcontextprotocol/java-sdk.git (GITHUB):
Affected version(s) =v1.1.0 <v1.1.1Fix Suggestion:
Update to version v1.1.1https://github.com/modelcontextprotocol/java-sdk.git (GITHUB):
Affected version(s) >=v0.1.0 <v1.0.1Fix Suggestion:
Update to version v1.0.1io.modelcontextprotocol.sdk:mcp-core (JAVA):
Affected version(s) =1.1.0 <1.1.1Fix Suggestion:
Update to version 1.1.1io.modelcontextprotocol.sdk:mcp-core (JAVA):
Affected version(s) >=0.13.0 <1.0.1Fix Suggestion:
Update to version 1.0.1Related Resources (6)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Permissive Cross-domain Security Policy with Untrusted Domains
EPSS
Base Score:
0.03
