MCP Java SDK <1.0.1 Wildcard CORS Vulnerability
CVE-2026-34237 Published on March 31, 2026

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

NVD

Vulnerability Analysis

CVE-2026-34237 can be exploited with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
REQUIRED
Scope:
CHANGED
Confidentiality Impact:
LOW
Integrity Impact:
LOW
Availability Impact:
NONE

Weakness Type

Permissive Cross-domain Policy with Untrusted Domains

The software uses a cross-domain policy file that includes domains that should not be trusted.


Products Associated with CVE-2026-34237

Want to know whenever a new CVE is published for Oracle? stack.watch will email you.

Oracle
 

Affected Versions

modelcontextprotocol java-sdk:

Exploit Probability

EPSS
0.04%
Percentile
10.27%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.