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

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-111769— Model Context Protocol TypeScript SDK: HTTP client transports and OAuth requests followed cross-origin redirects and re-sent custom headers and request bodies

Quick assessment

Affected
modelcontextprotocol 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.

Model Context Protocol（MCP）TypeScript SDK 提供了该协议的 TypeScript 客户端和服务端实现。在 版本早于 1.32.0，以及 版本从 2.0.0 到 2.3.0 期间，HTTP 客户端传输层和 OAuth 客户端请求在跟随重定向至不同源（origin）时，会保留自定义请求头；对于 HTTP 307 或 308 响应，还会保留请求体。受影响的组件包括 、 以及 等 OAuth 客户端函数。触发条件为指向其他源的 HTTP 重定向。在此过程中，自定义请求头及 可能被重新

CVSS 6.5 · Medium
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-111769

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
Model Context Protocol TypeScript SDK: HTTP client transports and OAuth requests followed cross-origin redirects and re-sent custom headers and request bodies
Source: CVE Program / CVE List V5
Vulnerability Description
The Model Context Protocol TypeScript SDK provides TypeScript client and server implementations of the Model Context Protocol. Prior to 1.32.0 in @modelcontextprotocol/sdk and from 2.0.0 until 2.3.0 in @modelcontextprotocol/client, the HTTP client transports and OAuth client requests followed redirects to a different origin while retaining custom request headers and, for HTTP 307 or 308 responses, request bodies. The affected surfaces are StreamableHTTPClientTransport, SSEClientTransport, and OAuth client functions such as auth(). The trigger is an HTTP redirect to another origin. Custom headers and mcp-session-id can be re-sent to the redirected origin. HTTP 307 and 308 redirects can also re-send the request body. OAuth request bodies can contain refresh_token and client_secret values. Current runtimes already strip the Authorization header across origins. stdio clients do not use the affected HTTP path. A malicious or compromised MCP or authorization server could therefore receive API keys, session identifiers, OAuth refresh tokens, or OAuth client secrets. Restoring unrestricted redirect following after upgrading restores the exposure. This issue is fixed in @modelcontextprotocol/sdk 1.32.0 and @modelcontextprotocol/client 2.3.0.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
信息暴露
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
modelcontextprotocol typescript-sdk < 1.32.0 -
@modelcontextprotocol sdk < 1.32.0 -
@modelcontextprotocol client >= 2.0.0, < 2.3.0 -

II. Public POCs for CVE-2026-111769

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

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-111769

请登录查看更多情报信息。

Other References for CVE-2026-111769 (7)

Same Patch Batch · modelcontextprotocol · 2026-11-05 · 4 CVEs total

CVE-2026-111770 7.7 HIGH Model Context Protocol TypeScript SDK: Shared transport or server instances delivered one
CVE-2026-111768 7.5 HIGH Model Context Protocol TypeScript SDK: One HTTP request within the default size limit coul
CVE-2026-111771 6.8 MEDIUM Model Context Protocol TypeScript SDK: Server bearer authentication accepted tokens issued

IV. Related Vulnerabilities

Same product: typescript-sdk
Same vendor: modelcontextprotocol
Same weakness: CWE-200