{"id":"CVE-2023-39959","summary":"Existence of calendars and address books can be checked by unauthenticated users","details":"Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.9, 26.0.4, and 27.0.1, unauthenticated users could send a DAV request which reveals whether a calendar or an address book with the given identifier exists for the victim. Nextcloud Server versions 25.0.9, 26.0.4, and 27.0.1 and Nextcloud Enterprise Server versions 25.0.9, 26.0.4, and 27.0.1 contain a patch for this issue. No known workarounds are available.","aliases":["GHSA-g97r-8ffm-hfpj"],"modified":"2026-05-18T05:56:42.854899374Z","published":"2023-08-10T17:07:42.367Z","database_specific":{"cwe_ids":["CWE-284"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/39xxx/CVE-2023-39959.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://hackerone.com/reports/1832126"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/39xxx/CVE-2023-39959.json"},{"type":"ADVISORY","url":"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-g97r-8ffm-hfpj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-39959"},{"type":"FIX","url":"https://github.com/nextcloud/server/pull/38747"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/nextcloud/server","events":[{"introduced":"add4e4365a4040d2e4e6aa79c0d03c3edd78583c"},{"fixed":"e9174a418927eade3a1e6261978b27abdfdfcef6"}]}],"versions":["v27.0.1rc2","v27.0.1rc1","v27.0.0"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-39959.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N"}]}