Anthropic's MCP TypeScript SDK versions up to and including 1.25.1 contain a regular expression denial of service (ReDoS) vulnerability in the UriTemplate class when processing RFC 6570 exploded array patterns. The dynamically generated regular expression used during URI matching contains nested quantifiers that can trigger catastrophic backtracking on specially crafted inputs, resulting in excessive CPU consumption. An attacker can exploit this by supplying a malicious URI that causes the Node.js process to become unresponsive, leading to a denial of service.
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History
Tue, 06 Jan 2026 14:30:00 +0000
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Anthropic
Anthropic mcp Typescript Sdk |
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Anthropic
Anthropic mcp Typescript Sdk |
Tue, 06 Jan 2026 00:15:00 +0000
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ssvc
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Mon, 05 Jan 2026 21:00:00 +0000
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| Description | Anthropic's MCP TypeScript SDK versions up to and including 1.25.1 contain a regular expression denial of service (ReDoS) vulnerability in the UriTemplate class when processing RFC 6570 exploded array patterns. The dynamically generated regular expression used during URI matching contains nested quantifiers that can trigger catastrophic backtracking on specially crafted inputs, resulting in excessive CPU consumption. An attacker can exploit this by supplying a malicious URI that causes the Node.js process to become unresponsive, leading to a denial of service. | |
| Title | MCP TypeScript SDK UriTemplate Exploded Array Pattern ReDoS | |
| Weaknesses | CWE-1333 | |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: VulnCheck
Published:
Updated: 2026-01-05T21:48:30.567Z
Reserved: 2026-01-05T19:41:59.356Z
Link: CVE-2026-0621
Updated: 2026-01-05T21:07:49.707Z
Status : Received
Published: 2026-01-05T21:16:14.533
Modified: 2026-01-05T22:15:54.387
Link: CVE-2026-0621
No data.
OpenCVE Enrichment
Updated: 2026-01-06T14:16:36Z