CVE-2026-39422: MaxKB has Stored XSS via ChatHeadersMiddleware
MaxKB is an open-source AI assistant for enterprise. Versions 2.7.1 and below contain a Stored Cross-Site Scripting (XSS) vulnerability through the application name or icon fields when creating an application. When a victim visits the public chat interface (/ui/chat/{accesstoken}), the ChatHeadersMiddleware retrieves the application data and directly inserts the unescaped application name and icon into the HTML response via string replacement. This allows an attacker to execute arbitrary JavaScript in the victim's browser context. This issue has been fixed in version 2.8.0.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-39422?
CVE-2026-39422 is classified as a high severity Stored Cross-Site Scripting (XSS) vulnerability.
How do I fix CVE-2026-39422?
To fix CVE-2026-39422, upgrade MaxKB to version 2.8.0 or above.
What versions of MaxKB are affected by CVE-2026-39422?
MaxKB versions 2.7.1 and below are affected by CVE-2026-39422.
What is the impact of CVE-2026-39422?
CVE-2026-39422 allows attackers to execute arbitrary JavaScript in the context of the victim's browser, potentially leading to account hijacking or data theft.
How does the Stored XSS vulnerability in CVE-2026-39422 occur?
The Stored XSS vulnerability in CVE-2026-39422 occurs through malicious input in the application name or icon fields during application creation.