Stored XSS Vulnerability in FOSSBilling Client Email History
CVE-2026-53641

4.8MEDIUM

Key Information:

Vendor

Fossbilling

Status
Fossbilling
Vendor
CVE Published:
6 July 2026

What is CVE-2026-53641?

FOSSBilling, a free and open-source billing and client management system, has a vulnerability affecting versions 0.6.0 through 0.7.2, which allows for stored cross-site scripting (XSS) in the email history views. By rendering HTML content through a JavaScript template literal without appropriate output escaping, an attacker with admin privileges can inject arbitrary JavaScript payloads into client emails. This payload executes in the browser of any client accessing their email history, posing significant security risks. Upgrading to version 0.8.0 remedies this issue, while temporary mitigations include limiting admin access, auditing email content, and monitoring unusual behavior in client accounts.

Affected Version(s)

FOSSBilling >= 0.6.0, < 0.8.0

References

https://github.com/FOSSBilling/FOSSBilling/security/advis...
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CVSS V4

Score:
4.8
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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