{"schema":"threatline.record/2","record":{"id":"CVE-2026-111056","aliases":["GHSA-x4mh-g4pc-wfc5"],"summary":"FOSSBilling: Unauthenticated client account enumeration via guest signup endpoint","details":"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.","categories":["Unclassified"],"product":"FOSSBilling","vendor":"FOSSBilling","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-111056","source_modified_at":"2026-10-22T03:02:43.261Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"FOSSBilling","vendor":"FOSSBilling","versions":[{"version":">= 0.1.0, < 0.8.7","status":"affected"}],"defaultStatus":null},{"source":"GitHub Advisory Database","source_url":"https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-x4mh-g4pc-wfc5","source_modified_at":"2026-10-19T16:22:17Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"","name":"FOSSBilling"},"range":"<= 0.8.6"}],"fixed_versions":[{"source":"GitHub Advisory Database","source_url":"https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-x4mh-g4pc-wfc5","source_modified_at":"2026-10-19T16:22:17Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"","name":"FOSSBilling"},"version":"0.8.7"}],"cvss":6.9,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00285,"percentile":0.19995,"score_date":"2026-10-23"},"published_at":"2026-10-19T16:00:57.576Z","modified_at":"2026-10-22T03:02:43.261Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-111056","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-22T03:02:43.261Z"},{"source":"GitHub Advisory Database","url":"https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-x4mh-g4pc-wfc5","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-19T16:22:17Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-111056","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","GitHub Advisory Database","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-x4mh-g4pc-wfc5","tags":["x_refsource_CONFIRM"]},{"source":"CVE List","url":"https://github.com/FOSSBilling/FOSSBilling/pull/4234","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/FOSSBilling/FOSSBilling/commit/19f41ff0a45874c7362b7732c8f68db84bc59c55","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.7","tags":["x_refsource_MISC"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"yes","technical_impact":"partial","assessed_at":"2026-10-22T03:02:31.174115Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-22T03:02:43.261Z","content_hash":"edf5ac0d48769cb7db563e7ce17005c899f8f07de877f0da44f14a73206ba0b5"}}