PT-2026-46062 · Fossbilling · Fossbilling

Published 2026-06-03 · Updated 2026-06-03 · CVE-2026-43924

NVD

CVSS v4.0

4.8

Medium

Base vector

AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:N/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

FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.0, the Redirect module does not validate the URL scheme of administrator-configured destination URLs before storing or issuing redirects. This allows arbitrary external URLs to be configured as redirect targets, creating an open redirect vulnerability exploitable for phishing attacks. Users following a legitimate FOSSBilling URL can be silently redirected to an attacker-controlled external site. The redirect is issued as a 301 (Moved Permanently) response, which browsers cache persistently, amplifying the impact. Exploitation requires administrator privileges to create or modify redirect entries, limiting practical attack scenarios to multi-admin environments or compromised admin accounts. Version 0.8.0 fixes the issue. Some workarounds are available. Restrict admin access to the Redirect module to trusted administrators only and/or audit existing redirect entries in the database (the extension meta table with extension = 'mod redirect') for any unexpected or external target URLs.

Fix

Open Redirect

Weakness Enumeration

CWE-601

Related Identifiers

CVE-2026-43924

Affected Products

Fossbilling

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-43924 · Security Note
• https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-v8rf-g37v-vgpx · Note
• https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.0 · Note