MaxKB, an open-source AI assistant for enterprise use, contains a stored XSS vulnerability (CWE-79) due to improper neutralization of input during web page generation. Specifically, versions prior to 2.8.0 have an Eval Injection issue in the Markdown rendering engine that permits any user interacting with the AI chat interface to inject and execute arbitrary JavaScript code in the browsers of other users, including those with administrative privileges. This vulnerability allows persistent script injection, which can lead to session hijacking, unauthorized actions, or other malicious activities within the affected application context. The issue is resolved in MaxKB version 2.8.0.

Successful exploitation allows an attacker with user-level access to inject and execute arbitrary JavaScript in the browsers of other users, including administrators. This can lead to unauthorized actions performed with elevated privileges, session hijacking, or other malicious impacts typical of stored XSS vulnerabilities. The vulnerability affects versions 2.7.1 and below of MaxKB. There are no known exploits in the wild at this time.

Upgrade MaxKB to version 2.8.0 or later, where this vulnerability has been fixed. Since this is not a cloud service, remediation depends on applying the official update. Patch status is confirmed by the vendor's versioning information. No additional mitigation steps are indicated by the vendor advisory.