The Model Context Protocol TypeScript SDK provides TypeScript client and server implementations of the Model Context Protocol.
CVE-2026-111768
The Model Context Protocol TypeScript SDK provides TypeScript client and server implementations of the Model Context Protocol. From 1.3.0 until 1.32.0 in @modelcontextprotocol/sdk and from 2.0.0 until 2.3.0 in @modelcontextprotocol/server, HTTP servers did not enforce a limit on the number of array elements and object keys validated in one request. The affected surface is validation of HTTP requests containing arrays or object keys. The trigger is an array-element or object-key validation workload large enough to exhaust memory while remaining within the request size limit. A single request within the default 4 MiB limit can terminate the process with JavaScript heap exhaustion. No credentials are required unless the application authenticates before SDK processing. Tools accepting arrays or records carry the greatest risk. stdio-only servers do not expose the HTTP request path. Upgrading alone does not enable the new validation bound. Operators must configure both a tool-input element bound and an appropriate request body size limit. This issue is fixed in @modelcontextprotocol/sdk 1.32.0 and @modelcontextprotocol/server 2.3.0.
Part of the AI stack
This affects Model Context Protocol, in MCP & tool servers.
Assessment
- CVSS
- 7.5 (v3.1)
- Severity
- High
- EPSS
- 0.6% chance of exploitation in the next 30 days
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 5 November 2026
- Last updated
- 9 November 2026
- Affected
- @modelcontextprotocol · modelcontextprotocol · SDK · Server · typescript-sdk
- Assigner
- GitHub_M
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
At the source
References
- https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-46jr-4wx8-v453
- https://github.com/modelcontextprotocol/typescript-sdk/pull/2926
- https://github.com/modelcontextprotocol/typescript-sdk/pull/2927
- https://github.com/modelcontextprotocol/typescript-sdk/commit/6d8dbc6cb590edf766fcb66b636ca6b654e99c37
- https://github.com/modelcontextprotocol/typescript-sdk/commit/fd26801b3b387742fe24a90ed4b275dd6072209f
- https://github.com/modelcontextprotocol/typescript-sdk/releases/tag/1.32.0
- https://github.com/modelcontextprotocol/typescript-sdk/releases/tag/@modelcontextprotocol/server@2.3.0
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