Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-0621— MCP TypeScript SDK UriTemplate Exploded Array Pattern ReDoS

Quick assessment

Affected
Anthropic MCP TypeScript SDK
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

MCP TypeScript SDK是Model Context Protocol开源的一个用于模型上下文协议服务器和客户端的开发者工具包。 MCP TypeScript SDK 1.25.1及之前版本存在安全漏洞，该漏洞源于UriTemplate类处理RFC 6570爆炸数组模式时存在正则表达式拒绝服务，可能导致CPU消耗过高和拒绝服务攻击。

AI Predicted 7.5 Difficulty: Moderate EPSS 0.41% · P34

Affected Version Matrix 1

VendorProduct Version RangeStatus
Anthropic MCP TypeScript SDK ≤ 1.25.1 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-0621

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
MCP TypeScript SDK UriTemplate Exploded Array Pattern ReDoS
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
CWE-1333
Source: CVE Program / CVE List V5
Vulnerability Title
MCP TypeScript SDK 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
MCP TypeScript SDK是Model Context Protocol开源的一个用于模型上下文协议服务器和客户端的开发者工具包。 MCP TypeScript SDK 1.25.1及之前版本存在安全漏洞，该漏洞源于UriTemplate类处理RFC 6570爆炸数组模式时存在正则表达式拒绝服务，可能导致CPU消耗过高和拒绝服务攻击。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Anthropic MCP TypeScript SDK 0 ~ 1.25.1 -

II. Public POCs for CVE-2026-0621

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-0621

请登录查看更多情报信息。

Other References for CVE-2026-0621 (2)

IV. Related Vulnerabilities

Same vendor: Anthropic
Same weakness: CWE-1333

V. Comments for CVE-2026-0621

No comments yet

Leave a comment