CVE-2026-0621

描述

### Impact A ReDoS vulnerability in the `UriTemplate` class allows attackers to cause denial of service. The `partToRegExp()` function generates a regex pattern with nested quantifiers (`([^/]+(?:,[^/]+)*)`) for exploded template variables (e.g., `{/id*}`, `{?tags*}`), causing catastrophic backtracking on malicious input. **Who is affected:** MCP servers that register resource templates with exploded array patterns and accept requests from untrusted clients. **Attack result:** An attacker sends a crafted URI via `resources/read` request, causing 100% CPU utilization, server hang/crash, and denial of service for all clients. ### Affected Versions All versions of `@modelcontextprotocol/sdk` prior to the patched release. ### Patches v1.25.2 contains b392f02ffcf37c088dbd114fedf25026ec3913d3 the fix modifies the regex pattern to prevent backtracking. ### Workarounds - Avoid using exploded patterns (`{/id*}`, `{?tags*}`) in resource templates - Implement request timeouts and rate limiting - Validate URIs before processing to reject suspicious patterns

如何修補 CVE-2026-0621

要修補 CVE-2026-0621,請將受影響套件升級到下列已修補版本。

• —升級至 1.25.2 或更新版本

CVE-2026-0621 正在被利用嗎?

低 — EPSS 為 0.4%,目前沒有觀察到大規模利用活動。

受影響套件(1)

• >= 1.3.0, < 1.25.2

CVSS 分數

參考連結(8)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2026-0621
• PATCHgithub.com/modelcontextprotocol/typescript-sdk
• WEBgithub.com/modelcontextprotocol/typescript-sdk/commit/7f0cf730
• WEBgithub.com/modelcontextprotocol/typescript-sdk/commit/b392f02ffcf37c088dbd114fedf25026ec3913d3