CVE-2026-53711: MCP ContextForge: Global Prompts stored cross-site scripting compromises the Admin UI
MCP Context Forge provides an MCP Admin UI for managing gateway resources. From 0.2.0 until 0.3.1, the Global Prompts feature stores a prompt template without sufficient output encoding before the MCP Admin UI renders it. An authenticated attacker can save markup containing script-capable event handlers, and the code executes when another user views the saved prompt. The stored cross-site scripting can alter the interface, present phishing content, observe keystrokes available to the page, and act with the viewer's browser session. This issue is fixed in version 0.3.1.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
MCP Context Forgeto a version that resolves this vulnerability.Fixed in 0.3.1
Event History
Frequently Asked Questions
Who can exploit this issue, and who is at risk when it is triggered?
An authenticated user who can save a Global Prompt can store markup with script-capable event handlers. Any other user who later views that saved prompt in the MCP Admin UI may have code execute in their browser session.
Are default deployments affected?
The available information identifies the Global Prompts feature as the affected component, but does not state whether it is enabled or accessible by default. Exposure depends on whether authenticated users can create or modify Global Prompts and whether other users view them.
What can be done if upgrading is not immediately possible?
The provided information does not document a workaround. Restrict access to creating or editing Global Prompts to trusted users and avoid viewing untrusted saved prompts until the deployment can be updated.
How can administrators identify possible compromise?
Review existing Global Prompts for markup containing script-capable event handlers, especially prompts created by untrusted or unexpected authenticated users. Affected viewers may have been exposed when they opened those prompts in the Admin UI.
Which versions need remediation?
Versions from 0.2.0 until 0.3.1 are affected. The issue is fixed in version 0.3.1.