{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-45286", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-05-11T20:14:43.200Z", "datePublished": "2026-06-01T16:59:36.865Z", "dateUpdated": "2026-06-01T19:13:25.363Z"}, "containers": {"cna": {"title": "Nextcloud: Calendar app leaked user identifiers via attendee suggestion endpoint", "problemTypes": [{"descriptions": [{"cweId": "CWE-200", "lang": "en", "description": "CWE-200: Exposure of Sensitive Information to an Unauthorized Actor", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-r697-74m9-gvf2", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-r697-74m9-gvf2"}, {"name": "https://github.com/nextcloud/calendar/issues/7971", "tags": ["x_refsource_MISC"], "url": "https://github.com/nextcloud/calendar/issues/7971"}, {"name": "https://github.com/nextcloud/calendar/pull/8197", "tags": ["x_refsource_MISC"], "url": "https://github.com/nextcloud/calendar/pull/8197"}, {"name": "https://hackerone.com/reports/3540663", "tags": ["x_refsource_MISC"], "url": "https://hackerone.com/reports/3540663"}], "affected": [{"vendor": "nextcloud", "product": "security-advisories", "versions": [{"version": ">= 5.5.13, < 5.5.17", "status": "affected"}, {"version": ">= 6.2.0, < 6.2.3", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-06-01T16:59:36.865Z"}, "descriptions": [{"lang": "en", "value": "Nextcloud is an open source content collaboration platform. From versions 5.5.13 to before 5.5.17, and 6.2.0 to before 6.2.3, an authenticated user can enumerate users on the same Nextcloud instance by using the Calendar app's endpoint for suggesting attendees. The sharing restrictions, applied to other endpoints, were not effective here. This issue has been patched in versions 5.5.17 and 6.2.3."}], "source": {"advisory": "GHSA-r697-74m9-gvf2", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-06-01T19:12:56.174122Z", "id": "CVE-2026-45286", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"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": "2026-06-01T19:13:25.363Z"}}]}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "Nextcloud is an open source content collaboration platform. From versions 5.5.13 to before 5.5.17, and 6.2.0 to before 6.2.3, an authenticated user can enumerate users on the same Nextcloud instance by using the Calendar app's endpoint for suggesting attendees. The sharing restrictions, applied to other endpoints, were not effective here. This issue has been patched in versions 5.5.17 and 6.2.3."}], "id": "CVE-2026-45286", "lastModified": "2026-06-01T19:16:50.957", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-06-01T19:16:50.957", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/nextcloud/calendar/issues/7971"}, {"source": "security-advisories@github.com", "url": "https://github.com/nextcloud/calendar/pull/8197"}, {"source": "security-advisories@github.com", "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-r697-74m9-gvf2"}, {"source": "security-advisories@github.com", "url": "https://hackerone.com/reports/3540663"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-200"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}