FOSSBilling up to 0.7.2 Email History View content_html cross site scripting

Summaryinfo

A vulnerability labeled as problematic has been found in FOSSBilling up to 0.7.2. Impacted is an unknown function of the component Email History View. Such manipulation of the argument content_html leads to cross site scripting. This vulnerability is listed as CVE-2026-53641. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in FOSSBilling up to 0.7.2. It has been rated as problematic. Affected by this issue is an unknown part of the component Email History View. The manipulation of the argument content_html with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to 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. Impacted is integrity. CVE summarizes:

FOSSBilling is a free, open-source billing and client management system. Versions 0.6.0 through 0.7.2 have a stored cross-site scripting (XSS) vulnerability in the client-facing email history views of FOSSBilling. Email HTML content (`content_html`) is rendered into a JavaScript template literal using the `|raw` filter, bypassing all output escaping. An attacker with admin access can inject malicious JavaScript payloads into email content that execute in the browser of any client who views their email history. Version 0.8.0 contains a fix. Some workarounds are available. Restrict admin account access, audit email content in the database for suspicious payloads, and/or monitor client accounts for unusual activity.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-53641 since 06/09/2026. The exploitation is known to be easy. The attack may be launched remotely. Additional levels of successful authentication are necessary for exploitation. 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 0.8.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-41966). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Billing Software

Name

• FOSSBilling

Version

• 0.7.0
• 0.7.1
• 0.7.2

Website

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

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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