The vulnerability arises because Agent Zero Web UI before version 1.15 fails to apply proper sanitization to user‑provided content in chat messages or uploaded files. When the application re‑renders this content, malicious JavaScript injected by an attacker is executed in the context of the victim’s authenticated web session. This allows the attacker to hijack session cookies, read or modify protected data, and perform any actions that the authenticated user is authorized to do, thereby compromising confidentiality, integrity, and potentially availability of the system.

The affected product is Agent Zero, specifically any installation running a version older than 1.15. The issue exists in the chat interface and the file‑upload functionality of the web UI and is vendor specific to Agent Zero’s platform. No other vendors or product lines are listed as affected.

The CVSS score of 8.6 classifies this as a high‑severity flaw. The EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog, indicating that no publicly known exploits have been observed at the time of this analysis. The attack vector is likely a local or remote authenticated user able to interact with the chat or file upload features; the attacker only needs to supply crafted input. Given the lack of exploitation evidence but the high potential impact, organizations using pre‑1.15 releases should treat this as a significant risk pending patch.