CVE-2025-59899 Authenticated Cross-Site Scripting (XSS) vulnerability in Sync Breeze Enterprise Server

Medium 5.1 Published 28 Jan 2026 Updated 28 Jan 2026

An authenticated attacker can inject malicious scripts into server options, potentially stealing session information from other users.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2025-59899?

CVE-2025-59899 is a medium-severity cross-site scripting vulnerability in Flexense Disk Pulse Enterprise, published on 28 Jan 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

Sync Breeze Enterprise Server v10.4.18 and Disk Pulse Enterprise v10.4.18 contain a persistent authenticated Cross-Site Scripting (XSS) vulnerability. An attacker could send malicious content to an authenticated user and steal information from their session due to insufficient validation of user input in '/server_options?sid=', affecting the 'tasks_logs_dir', 'errors_logs_dir', 'error_notifications_address', 'status_notifications_address', and 'status_reports_address' parameters.

Weakness: CWE-79

Which versions are affected by CVE-2025-59899?

It affects 2 products.

Products include Flexense Diskpulse, Flexense Syncbreeze.

How do I fix CVE-2025-59899?

No fix has been published for CVE-2025-59899 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2025-59899 being exploited?

There is no known exploitation of CVE-2025-59899 in the wild and no public exploit code.

Sources

Also known as GHSA-cg8j-jfqg-q55w.