Resource exhaustion in @Modelcontextprotocol Sdk

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.

Published .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-111768?
CVE-2026-111768 is a high-severity vulnerability in @Modelcontextprotocol Sdk, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-11-05.
How severe is CVE-2026-111768?
High severity. CVSS v3 base score is 7.5 out of 10.