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archive/Patch now/AIR-2026-1432
closedclosed 20 Oct 2026Patch now2 Disclosed vulnerabilityAI

CVE-2026-111769: MCP TypeScript client SDK leaked custom headers on cross-origin redirects

MCP TypeScript SDK

HTTP client transports and OAuth requests in the MCP TypeScript SDK followed cross-origin redirects, improperly re-sending sensitive custom headers and request bodies. This could expose authorization tokens and credentials to untrusted third-party servers.

disclosed CVENo confirmed exploitation, so this record is tracked as a disclosed vulnerability and not counted as an incident. It moves into the counts if CISA or the vendor confirms exploitation. Why

CVSS
6.5
EPSS
<0.01 · top 65% · 2026-11-13
EPSS scores by FIRST
fix status
Fix status unknown
first report
20 Oct 2026
last update
5 Nov 2026
CVE ids
CVE-2026-111769other records

Timeline · 2

  1. 20 Oct 2026CVE-2026-111769: MCP TypeScript client SDK: HTTP client transports and OAuth requests followed cross-origin redirects and re-sent custom headers and request…
  2. 5 Nov 2026NVD record published

Sources · 2

Advisories and databases

  1. 2026-10-20
    CVE-2026-111769: MCP TypeScript client SDK: HTTP client transports and OAuth requests followed cross-origin redirects and re-sent custom headers and request…
    GitHub Advisory Database · github.com/advisories/GHSA-6prh-2h8m-c8cw
  2. 2026-11-05
    CVE-2026-111769: The Model Context Protocol TypeScript SDK provides TypeScript client and server implementations of the Model Context Protocol.
    NVD · nvd.nist.gov/vuln/detail/CVE-2026-111769

Titles and links belong to their publishers. The summary above is written by gcdRadar in its own words; data is CC BY-SA 4.0.

Classification

lane
Patch now
AI role
Attack on AI
categories
Infrastructure vulnerability
severity
2 · Disclosed vulnerability
fix status
Fix status unknown
targets
Framework / tooling
owasp llm top 10
LLM03:2025 Supply Chain
mitre atlas
no technique for these categories
tags
mcpoauthredirect
dates
happened 20 Oct 2026 · first reported 20 Oct 2026
origin
GitHub Advisory Database
Vulnerability record from NVD / the GitHub Advisory Database. This product uses the NVD API but is not endorsed or certified by the NVD.
record
confidence 0.95 · created 2026-10-20 22:08Z · updated 2026-11-06 00:23Z

Lane, AI role, categories and severity come from the classifier; the OWASP and ATLAS rows are derived from the categories. How these are assigned

Copy a brief

This record as a short Markdown brief, for a ticket, a chat or a coding agent.

the brief as text
# CVE-2026-111769: MCP TypeScript client SDK leaked custom headers on cross-origin redirects

https://gcdradar.vercel.app/incidents/cve-2026-111769-mcp-typescript-client-sdk-leaked-custom-head · AIR-2026-1432 · closed 2026-10-20

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability)
- Fix status: Fix status unknown
- First reported: 2026-10-20
- AI role: Attack on AI
- Products: MCP TypeScript SDK
- CVE ids: CVE-2026-111769
- CVSS: 6.5

## Summary

HTTP client transports and OAuth requests in the MCP TypeScript SDK followed cross-origin redirects, improperly re-sending sensitive custom headers and request bodies. This could expose authorization tokens and credentials to untrusted third-party servers.

## What to do

No action recorded; read the sources below and the vendor's advisory.

## Latest updates

- 2026-11-05: NVD record published (https://nvd.nist.gov/vuln/detail/CVE-2026-111769)
- 2026-10-20: CVE-2026-111769: MCP TypeScript client SDK: HTTP client transports and OAuth requests followed cross-origin redirects and re-sent custom headers and request… (https://github.com/advisories/GHSA-6prh-2h8m-c8cw)

## Sources

- 2026-10-20 GitHub Advisory Database: CVE-2026-111769: MCP TypeScript client SDK: HTTP client transports and OAuth requests followed cross-origin redirects and re-sent custom headers and request… https://github.com/advisories/GHSA-6prh-2h8m-c8cw
- 2026-11-05 NVD: CVE-2026-111769: The Model Context Protocol TypeScript SDK provides TypeScript client and server implementations of the Model Context Protocol. https://nvd.nist.gov/vuln/detail/CVE-2026-111769

Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.

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