FOSSBilling: Low-privileged staff can run JavaScript in administrators' browsers via stored XSS in support ticket notes
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 0.8.9
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affected FOSSBilling versions 0.1.0 through 0.8.8. Attacker needs the support.manage_tickets staff permission.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 16/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fixed in 0.8.9
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
FOSSBilling, an open source billing and client-management platform, is affected from versions 0.1.0 through 0.8.9. A staff member with only limited support-ticket permissions can save malicious scripts in ticket notes that run in the browser of any other staff member who opens them, including administrators, letting the attacker act with the viewer's privileges and access client and invoice data.
Read the original description
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.
What to do
Check whether your setup matches what the bug needs.
Affected FOSSBilling versions 0.1.0 through 0.8.8. Attacker needs the support.manage_tickets staff permission.Upgrade to a fixed version: 0.8.9.
Workaround: Revoke the support.manage_tickets permission from staff groups that do not need it.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- FOSSBilling FOSSBilling
From 0.1.0 · fixed in 0.8.9
Evidence 4
- Advisory
- Repository
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-111048
What does this mean?
A staff member who has only the support.manage_tickets permission can save a support ticket note containing JavaScript. When another staff member views that note, the script runs in their browser with their session and privileges, including a Super Administrator's, so it can read the CSRF token, read viewable client and invoice data, and take administrative actions.Source: github.com
Am I affected, and how do I check?
FOSSBilling versions 0.1.0 through 0.8.8 are affected, per the advisory's statement that all releases to date in that range are affected. To check, look at the installed FOSSBilling version in the admin panel, and check whether any staff group has the support.manage_tickets permission.Source: github.com
What should I do about it?
Upgrade FOSSBilling to version 0.8.9, which is the listed patched version.Source: github.com
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data