{
    "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"
                }
            }
        ]
    }
}