CVE-2026-53711: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in IBM mcp-context-forge
Description
IBM mcp-context-forge versions from 0.2.0 up to but not including 0.3.1 contain a stored cross-site scripting (XSS) vulnerability in the Global Prompts feature. This flaw allows an authenticated attacker to save malicious markup with script-capable event handlers that execute when another user views the prompt in the MCP Admin UI. The vulnerability is fixed in version 0.3.1.
CVSS v4.0
Score 5.1medium
Affected software
IBM
mcp-context-forge
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in IBM mcp-context-forge arises from improper output encoding of prompt templates in the Global Prompts feature between versions 0.2.0 and 0.3.0 inclusive. An authenticated attacker can inject markup containing script event handlers that execute in the context of another user's browser session when viewing the saved prompt. This stored cross-site scripting (CWE-79) can be used to alter the interface, present phishing content, capture keystrokes, and act with the privileges of the victim's session. The issue is resolved in version 0.3.1.
Potential Impact
An authenticated attacker can execute arbitrary scripts in the context of other users' browsers when they view the stored prompt templates. This can lead to interface manipulation, phishing attacks, keystroke logging, and unauthorized actions performed with the victim's session privileges. The CVSS 4.0 base score is 5.1 (medium severity), reflecting network attack vector, low attack complexity, and limited privileges required.
Mitigation Recommendations
Upgrade IBM mcp-context-forge to version 0.3.1 or later, where this stored cross-site scripting vulnerability is fixed. No other mitigation is specified or required.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-10T16:43:31.241Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ace44e72cdf04f656782987
Added to database: 10/13/2026, 14:49:11 UTC
Last enriched: 10/13/2026, 15:03:50 UTC
Last updated: 10/13/2026, 15:08:23 UTC
Views: 5
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