AgentFlow by Flowring contains a stored cross‑site scripting weakness that lets an authenticated remote attacker persistently inject malicious JavaScript into the application. When a victim later loads the affected pages, the injected script runs in the victim’s browser, potentially allowing session hijacking, data theft, or further client‑side attacks. The impact is primarily client‑side compromise, leading to possible theft of sensitive information or malicious interactions governed by the privileges of the logged‑in user.

The affected product is Flowring’s AgentFlow. Versions older than 4.0.0.1878.877 are vulnerable; any deployment using those releases must be examined. No other vendors or products are listed as impacted by this issue.

The CVSS base score of 5.1 indicates moderate severity. The EPSS score below 1% suggests that exploitation is currently unlikely, and the vulnerability is not present in CISA’s Known Exploited Vulnerabilities catalog. The likely attack vector requires the attacker to first authenticate to AgentFlow, after which they can inject the persistent script. Once injected, the script will execute on every page load for any user viewing that content, providing the attacker with repeat access to client‑side capabilities.