CVE-2026-34237

MEDIUMNVD 6.16.1—

6.1

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.

CVSS v3: 6.1
EG Score: 6.1(medium)
EPSS: 2.0%
KEV: Not listed

Published

March 31, 2026

Last Modified

April 3, 2026

References (3)

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

Affected Packages

(1 across 1 ecosystem)

Maven(1)

Package	Vulnerable range	Fixed in	Dependents
io.modelcontextprotocol.sdk:mcp-core	1.1.0	1.1.1	—

Data Freshness Timeline

(refreshed 16× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-31 22:30 UTCepss_batch
2026-05-31 22:30 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-29 13:44 UTCepss_batch
2026-05-29 13:44 UTCepss_batch
2026-05-28 13:44 UTCepss_batch
2026-05-28 13:44 UTCepss_batch
2026-05-28 13:44 UTCepss_batch
2026-05-27 13:40 UTCepss_batch
2026-05-27 13:40 UTCepss_batch
2026-05-27 13:40 UTCepss_batch
2026-05-26 13:44 UTCepss_batch
2026-05-26 07:18 UTCepss_batch
2026-05-26 07:18 UTCepss_batch
2026-05-23 00:09 UTCEG score recompute
2026-05-20 22:38 UTCepss_batch
2026-05-20 22:38 UTCepss_batch
2026-05-20 19:47 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-34237?

CVE-2026-34237 is a medium vulnerability published on March 31, 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.

When was CVE-2026-34237 disclosed?

CVE-2026-34237 was first published in the National Vulnerability Database on March 31, 2026, with the most recent update on April 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2026-34237 actively exploited?

CVE-2026-34237 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2026-34237?

CVE-2026-34237 has a CVSS v3 base score of 6.1 (NVD).

How do I remediate CVE-2026-34237?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-34237, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-34237

Explore →

Is Your Infrastructure Affected by CVE-2026-34237?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs

CVE-2026-34237

📅 Published

🔄 Last Modified

🔗 References (3)