CVE-2026-34237
unknown
CVSS v3
—
CVSS v4 NEW
—
VIR risk
—
Description
MCP Java SDK has a Hardcoded Wildcard CORS (Access-Control-Allow-Origin: *)
Predictions
Exploit likelihood
30%
Patch ETA
—
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Maven | io.modelcontextprotocol.sdk:mcp-core | <1.0.1 | 1.0.1 |
| Maven | io.modelcontextprotocol.sdk:mcp-core | >=1.1.0,<1.1.1 | 1.1.1 |
References
- https://github.com/modelcontextprotocol/java-sdk/security/advisories/GHSA-hv2w-8mjj-jw22
- https://nvd.nist.gov/vuln/detail/CVE-2026-34237
- https://cheatsheetseries.owasp.org/cheatsheets/HTTP_Headers_Cheat_Sheet.html#access-control-allow-origin
- https://github.com/modelcontextprotocol/java-sdk
- https://github.com/modelcontextprotocol/java-sdk/blob/main/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletSseServerTransportProvider.java#L289
- https://github.com/modelcontextprotocol/java-sdk/blob/main/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletStreamableServerTransportProvider.java#L525
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.