CVE-2026-108395
CVE-2026-108395 · Model Context Protocol Java SDK HTTP server transports allow memory exhaustion through unbounded request bodies
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 7.5 · High · EPSS 0.6%
- Published
- Updated
Affected products and versions
io.modelcontextprotocol.sdk:mcp
- Versions
- >= 0.8.0, < 0.13.0: Affected
No fix published
io.modelcontextprotocol.sdk:mcp-core
- Versions
- >= 0.13.0, < 0.18.4: Affected
- >= 1.0.0, < 1.1.4: Affected
- >= 2.0.0-M1, < 2.0.1: Affected
No fix published
Original sources
- https://github.com/modelcontextprotocol/java-sdk/security/advisories/GHSA-4x8c-5vv7-973f
- 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://nvd.nist.gov/vuln/detail/CVE-2026-108395