CVE-2026-0621

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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/modelcontextprotocol/typescript-sdk/issues/965	Exploit Issue Tracking
https://www.vulncheck.com/advisories/mcp-typescript-sdk-uritemplate-exploded-array-pattern-redos	Third Party Advisory
https://github.com/modelcontextprotocol/typescript-sdk/issues/965	Exploit Issue Tracking

Configurations

Configuration 1 (hide)

cpe:2.3:a:lfprojects:mcp_typescript_sdk:*:*:*:*:*:*:*:*

History

26 Oct 2026, 21:10

Type	Values Removed	Values Added
Summary		(es) Las versiones del SDK de TypeScript MCP de Anthropic hasta la 1.25.1 inclusive contienen una vulnerabilidad de denegación de servicio por expresión regular (ReDoS) en la clase UriTemplate al procesar patrones de array expandidos de RFC 6570. La expresión regular generada dinámicamente utilizada durante la coincidencia de URI contiene cuantificadores anidados que pueden desencadenar un retroceso catastrófico en entradas especialmente diseñadas, lo que resulta en un consumo excesivo de CPU. Un atacante puede explotar esto al proporcionar una URI maliciosa que hace que el proceso de Node.js deje de responder, lo que lleva a una denegación de servicio.

Information

Published : 2026-01-05 21:16

Updated : 2026-10-26 21:10

NVD link : CVE-2026-0621

Mitre link : CVE-2026-0621

CVE.ORG link : CVE-2026-0621

JSON object : View

Products Affected

lfprojects

mcp_typescript_sdk

CWE

CWE-1333

Inefficient Regular Expression Complexity

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