The Model Context Protocol Java SDK is the official Java SDK for Model Context Protocol servers and clients. From version 0.8.0 through 0.12.0 in the io.modelcontextprotocol.sdk:mcp artifact, from 0.13.0 through 0.18.3 and 1.0.0 through 1.1.3 in io.modelcontextprotocol.sdk:mcp-core, and from mcp-core 2.0.0-M1 through 2.0.0, the Servlet-based SSE, Streamable HTTP, and Stateless server transports read an HTTP request body into memory without enforcing a maximum size. An unauthenticated remote client able to reach an affected transport can stream an arbitrarily large POST body, including with chunked transfer encoding, until the Java process exhausts its heap and becomes unavailable. Authentication, Origin or Host validation, or an upstream request-size limit can reject the request before the vulnerable read. The maintained mcp-core lines are fixed in versions 0.18.4, 1.1.4, and 2.0.1.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 2
- StatusReceived → Awaiting AnalysisNVD modified 2026-10-16 16:00
- First seenCVSS 7.5NVD modified 2026-10-14 20:17
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 8
- https://github.com/modelcontextprotocol/java-sdk/commit/1499df22c7023aa257223143a5dcf5b1db7ef80d
- https://github.com/modelcontextprotocol/java-sdk/commit/6a41dedaa0625551582d8247e5a4d78eae1131b2
- https://github.com/modelcontextprotocol/java-sdk/commit/8c0fdd1b1f76adba3ce7945d29f73fa2ddc66598
- https://github.com/modelcontextprotocol/java-sdk/commit/9e4d5fa827b6ba69457f5fd93573184789528efa
- https://github.com/modelcontextprotocol/java-sdk/releases/tag/v0.18.4
- https://github.com/modelcontextprotocol/java-sdk/releases/tag/v1.1.4
- https://github.com/modelcontextprotocol/java-sdk/releases/tag/v2.0.1
- https://github.com/modelcontextprotocol/java-sdk/security/advisories/GHSA-4x8c-5vv7-973f