CVE-2026-43924

June 4, 2026, 3:41 p.m.

4.8
Medium

Description

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.

Product(s) Impacted

Vendor Product Versions
Fossbilling
  • Fossbilling
  • <0.8.0

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-601
URL Redirection to Untrusted Site ('Open Redirect')
A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks.

*CPE(s)

Affected systems and software identified for this CVE.

Type Vendor Product Version Update Edition Language Software Edition Target Software Target Hardware Other Information
a fossbilling fossbilling <0.8.0 / / / / / / /

References

https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.0
https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-v8rf-g37v-vgpx

Tags

[email protected]
CWE-601
2026-06-03
CVE-2026-43924

CVSS Score

4.8 / 10

CVSS Data - 4.0

  • Attack Vector: NETWORK
  • Attack Complexity: LOW
  • Attack Requirements: NONE
  • Privileges Required: HIGH
  • User Interaction: PASSIVE
  • Scope:
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: NONE
  • Exploit Maturity: NOT_DEFINED

    • CVSS:4.0/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

    View Vector String

Timeline

Published: June 3, 2026, 8:16 p.m.
Last Modified: June 4, 2026, 3:41 p.m.

Status : Deferred

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.