CVE-2026-0621

npm/@modelcontextprotocol/sdk CVE-2026-0621: high

Anthropic's MCP TypeScript SDK has a ReDoS vulnerability

Action: Upgrade @modelcontextprotocol/sdk to 1.25.2 or later.

npm i @modelcontextprotocol/sdk@1.25.2

Affected

Fixed versions

Sources

• osv: GHSA-8r9q-7v3j-jr4g
• https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-cqwc-fm46-7fff
• https://nvd.nist.gov/vuln/detail/CVE-2026-0621
• https://github.com/modelcontextprotocol/typescript-sdk/issues/965
• https://github.com/modelcontextprotocol/typescript-sdk/commit/7f0cf730
• https://github.com/modelcontextprotocol/typescript-sdk/commit/b392f02ffcf37c088dbd114fedf25026ec3913d3
• https://github.com/modelcontextprotocol/typescript-sdk
• https://github.com/modelcontextprotocol/typescript-sdk/releases/tag/v1.25.2
• https://www.vulncheck.com/advisories/mcp-typescript-sdk-uritemplate-exploded-array-pattern-redos

CVE-2026-0621 · published 2026-01-05T21:30:33Z · modified 2026-09-10T03:50:59.009997048Z · JSON