FOSSBilling up to 0.8.8 Admin Ticket List Rendering mod_support_tickets.html.twig note cross site scripting

Summaryinfo

A vulnerability categorized as problematic has been discovered in FOSSBilling up to 0.8.8. This affects an unknown part of the file src/modules/Support/templates/admin/mod_support_tickets.html.twig of the component Admin Ticket List Rendering. The manipulation of the argument note results in cross site scripting. This vulnerability was named CVE-2026-111048. The attack may be performed from remote. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in FOSSBilling up to 0.8.8. Affected is an unknown functionality of the file src/modules/Support/templates/admin/mod_support_tickets.html.twig of the component Admin Ticket List Rendering. The manipulation of the argument note with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

FOSSBilling is an open source billing and client-management platform. From 0.1.0 until 0.8.9, the admin/support/note_create endpoint stores the note parameter without sanitization in the support_ticket_note table, and src/modules/Support/templates/admin/mod_support_tickets.html.twig renders each stored support ticket note through innerHTML in the admin ticket list. A staff user with only the support.manage_tickets permission can store HTML or JavaScript that executes when another staff member opens the ticket notes. The script runs with the viewing staff member's session and privileges, can read a CSRF token and accessible client or invoice data, and can perform administrative actions available to the viewer, including a Super Administrator. The ticket detail page is not affected because its Twig rendering uses autoescaping. This issue is fixed in version 0.8.9.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-111048 since 10/15/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 0.8.9 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Billing Software

Name

• FOSSBilling

Version

• 0.8.0
• 0.8.1
• 0.8.2
• 0.8.3
• 0.8.4
• 0.8.5
• 0.8.6
• 0.8.7
• 0.8.8

Website

• Product: https://github.com/FOSSBilling/FOSSBilling/

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