{"id":"CVE-2026-111056","revision":"f5ff64e14a4b447a8b95f3433fa043a1","records":[{"revision":"f5ff64e14a4b447a8b95f3433fa043a1","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-111056","aliases":[],"title":"FOSSBilling: Unauthenticated client account enumeration via guest signup endpoint","description":"FOSSBilling is an open source billing and client-management platform. From 0.1.0 until 0.8.7, the unauthenticated POST /api/guest/client/create endpoint reveals whether a submitted email belongs to a registered client because guest signup returns a distinct unredacted error when the submitted email already exists. The trigger is an unauthenticated request to POST /api/guest/client/create with a target email address. An attacker can compare the guest-signup response for a target email to determine whether the email belongs to an existing FOSSBilling client. Box\\Mod\\Client\\Api\\Guest::create returns the error after Client\\Service::clientAlreadyExists finds a matching record, and the API response exposes that exception message without redaction. This issue is fixed in version 0.8.7.","state":0,"publishedAt":"2026-10-19T16:00:57.576+00:00","modifiedAt":"2026-10-22T03:02:43.261+00:00","affected":[{"ecosystem":"Vendor product","name":"FOSSBilling","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"FOSSBilling\",\n                    \"product\": \"FOSSBilling\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 0.1.0, < 0.8.7\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","score":6.9,"severity":"MEDIUM"}],"references":["https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-x4mh-g4pc-wfc5","https://github.com/FOSSBilling/FOSSBilling/pull/4234","https://github.com/FOSSBilling/FOSSBilling/commit/19f41ff0a45874c7362b7732c8f68db84bc59c55","https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.7"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-111056","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-111056","identifiers":["CVE-2026-111056"]},"retained":false,"historicalAffected":[]}],"coverage":[]}