{"id":"CVE-2026-43924","summary":"FOSSBilling has an open redirect via administrator-configured redirect targets","details":"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.","aliases":["GHSA-v8rf-g37v-vgpx"],"modified":"2026-07-08T08:13:27.341340636Z","published":"2026-06-03T19:56:25.836Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-601"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43924.json"},"references":[{"type":"WEB","url":"https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43924.json"},{"type":"ADVISORY","url":"https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-v8rf-g37v-vgpx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43924"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/fossbilling/fossbilling","events":[{"introduced":"0"},{"fixed":"3bd35f5b2921d8a26a403142ae0408f95e6463cc"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"0.8.0"}]}}],"versions":["0.7.2","0.7.1","0.7.0","0.6.22","0.6.21","0.6.20","0.6.19","0.6.18","0.6.17","0.6.16","0.6.15","0.6.14","0.6.13","0.6.12","0.6.11","0.6.10","0.6.9","0.6.8","0.6.7","0.6.6","0.6.5","0.6.4","0.6.3","0.6.2","0.6.1","0.6.0","0.5.5","0.5.4","0.5.3","0.5.2","0.5.1","0.5.0","0.4.3","0.4.2","0.4.1","0.4.0","0.3.0","0.2.10","0.2.9","0.2.8","0.2.7","0.2.6","0.2.5","0.2.4","0.2.3","0.2.2","0.2.1","0.2.0","0.1.1","0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43924.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"}]}