{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-111056", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-10-15T12:47:13.664Z", "datePublished": "2026-10-19T16:00:57.576Z", "dateUpdated": "2026-10-22T03:02:43.261Z"}, "containers": {"cna": {"title": "FOSSBilling: Unauthenticated client account enumeration via guest signup endpoint", "problemTypes": [{"descriptions": [{"cweId": "CWE-200", "lang": "en", "description": "CWE-200: Exposure of Sensitive Information to an Unauthorized Actor", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-204", "lang": "en", "description": "CWE-204: Observable Response Discrepancy", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-307", "lang": "en", "description": "CWE-307: Improper Restriction of Excessive Authentication Attempts", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 6.9, "baseSeverity": "MEDIUM", "vectorString": "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", "version": "4.0"}}], "references": [{"name": "https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-x4mh-g4pc-wfc5", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-x4mh-g4pc-wfc5"}, {"name": "https://github.com/FOSSBilling/FOSSBilling/pull/4234", "tags": ["x_refsource_MISC"], "url": "https://github.com/FOSSBilling/FOSSBilling/pull/4234"}, {"name": "https://github.com/FOSSBilling/FOSSBilling/commit/19f41ff0a45874c7362b7732c8f68db84bc59c55", "tags": ["x_refsource_MISC"], "url": "https://github.com/FOSSBilling/FOSSBilling/commit/19f41ff0a45874c7362b7732c8f68db84bc59c55"}, {"name": "https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.7", "tags": ["x_refsource_MISC"], "url": "https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.7"}], "affected": [{"vendor": "FOSSBilling", "product": "FOSSBilling", "versions": [{"version": ">= 0.1.0, < 0.8.7", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-19T16:00:57.576Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-x4mh-g4pc-wfc5", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-10-22T03:02:31.174115Z", "id": "CVE-2026-111056", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-22T03:02:43.261Z"}}]}}

{}

{"affected": [{"affectedData": [{"product": "FOSSBilling", "vendor": "FOSSBilling", "versions": [{"status": "affected", "version": ">= 0.1.0, < 0.8.7"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-111056", "lastModified": "2026-10-22T04:17:29.873", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.9, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "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/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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-111056", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-22T03:02:31.174115Z", "version": "2.0.3"}}]}, "published": "2026-10-19T16:17:03.657", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/FOSSBilling/FOSSBilling/commit/19f41ff0a45874c7362b7732c8f68db84bc59c55"}, {"source": "security-advisories@github.com", "url": "https://github.com/FOSSBilling/FOSSBilling/pull/4234"}, {"source": "security-advisories@github.com", "url": "https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.7"}, {"source": "security-advisories@github.com", "url": "https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-x4mh-g4pc-wfc5"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-200"}, {"lang": "en", "value": "CWE-204"}, {"lang": "en", "value": "CWE-307"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}