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CVE-2026-34237

MCP Java SDK has a Hardcoded Wildcard CORS (Access-Control-Allow-Origin: *)

Published: Mar 31, 2026Updated: Jul 24, 2026 Sources: CVE List NVDCWE-942
6.1MEDIUM
NVD MITRE
EPSS Score
0.2%
Top 87.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:RS:CC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:CScope
Changed
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-942

Affected Products

modelcontextprotocol
oss-projectaka mcp, model context protocol
java-sdkMixed
AI / ML / ai-agent-tooling
lfprojects
oss-projectaka model context protocol servers, valkey, mcp servers, mlflow
mcp java sdkLibraryLibrary
AI / ML / notebook-mlops

Exploitability

Official Patch Available
Workaround Available
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References

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

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