CVE-2026-0621
7.5 · HIGHOverview
CVE-2026-0621 is a high-severity vulnerability affecting lfprojects mcp_typescript_sdk. It was published on January 5, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from lfprojects. Update mcp_typescript_sdk to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| lfprojects | mcp_typescript_sdk | 0 | Affected |
Frequently Asked Questions
What is CVE-2026-0621?
CVE-2026-0621 is a high-severity vulnerability affecting lfprojects mcp_typescript_sdk. It was published on January 5, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-0621?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-0621?
Check the references section for vendor advisories and patches from lfprojects. Update mcp_typescript_sdk to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-0621?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-0621 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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