4.8
MEDIUM CVSS 4.0
CVE-2026-53641
FOSSBilling has stored XSS in client email views via unescaped content in JavaScript template literal
Description

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.

INFO

Published Date :

July 6, 2026, 11:16 p.m.

Last Modified :

July 6, 2026, 11:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-53641 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM [email protected]
Solution
Update FOSSBilling to version 0.8.0 or later to fix the stored XSS vulnerability.
  • Update FOSSBilling to version 0.8.0 or later.
  • Restrict admin account access.
  • Audit email content for suspicious payloads.
  • Monitor client accounts for unusual activity.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-53641.

URL Resource
https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-q6c8-6r72-35f7
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-53641 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-53641 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-53641 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 06, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'FOSSBilling', 'product': 'FOSSBilling', 'versions': [{'status': 'affected', 'version': '>= 0.6.0, < 0.8.0'}]}]
    Added Description 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-79
    Added CWE CWE-838
    Added Reference https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-q6c8-6r72-35f7
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.