CVE-2025-59900: Flexense Sync Breeze Enterprise Server · XSS or 'Cross-site Scripting'
Affects Flexense Sync Breeze Enterprise ServerSource CVE Database V5
Not known to be exploited · CVSS 5.1 Medium.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 28 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| FlexenseSync Breeze Enterprise Server | Affected
| Fixed in– |
| FlexenseDisk Pulse Enterprise | Affected
| Fixed in– |
AI-suggested
European organizations should immediately restrict access to the Sync Breeze Enterprise Server management interface to trusted administrators only, ideally via VPN or segmented network zones. Implement strict input validation and output encoding on all user-supplied data in the affected parameters, either by applying vendor patches when available or by deploying web application firewalls (WAFs) with custom rules to detect and block malicious payloads targeting '/server_options?sid='. Conduct thorough credential audits and enforce multi-factor authentication (MFA) to reduce the risk of unauthorized authenticated access. Regularly monitor server logs for unusual parameter values or repeated access attempts to the vulnerable endpoint. Educate administrators about the risks of XSS and the importance of not clicking on suspicious links or content within the server interface. If patching is not immediately possible, consider disabling or limiting the functionality of the affected parameters temporarily. Finally, maintain an incident response plan ready to address potential session hijacking or data leakage incidents stemming from this vulnerability.
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.