{"schema_version":1,"title":"Nextcloud Calendar vulnerabilities","summary":"Junglewise Threat Intelligence has tracked 4 vulnerabilities in Nextcloud Calendar: 0 in the last 7 days and 0 in the last 90 days, 0 of them critical and 0 exploited in the wild. The most recent, CVE-2026-45286, was published on 1 June 2026.","url":"https://junglewise.ai/threats/technologies/calendar","json_url":"https://junglewise.ai/threats/technologies/calendar.json","publisher":"Junglewise Threat Intelligence","license":"CC-BY-4.0","license_url":"https://creativecommons.org/licenses/by/4.0/","attribution":"Junglewise Threat Intelligence, https://junglewise.ai/threats/technologies/calendar","sources":"NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories","kind":"technology","thin":true,"counts":{"high":0,"all_time":4,"critical":0,"exploited":0,"last_7_days":0,"last_30_days":0,"last_90_days":0,"last_365_days":4},"latest":[{"cve":"CVE-2026-45286","cvss":4.3,"slug":"cve-2026-45286-nextcloud-calendar-user-enumeration-via-attendee-suggestion","title":"Nextcloud Calendar user enumeration via attendee suggestion endpoint","severity":"medium","exploited":false,"published_at":"2026-06-01T19:16:50.957+00:00","url":"https://junglewise.ai/threats/cve-2026-45286-nextcloud-calendar-user-enumeration-via-attendee-suggestion"},{"cve":"CVE-2025-66550","cvss":5.7,"epss":0.0034,"slug":"cve-2025-66550-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-4-7","title":"Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.17 and 5.2.4, when a malicious user creates a…","severity":"medium","exploited":false,"published_at":"2025-12-05T17:16:05.5+00:00","url":"https://junglewise.ai/threats/cve-2025-66550-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-4-7"},{"cve":"CVE-2025-66546","cvss":3.3,"epss":0.0014,"slug":"cve-2025-66546-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-4-7","title":"Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.19, 5.5.6, and 6.0.1, the calendar app allowed…","severity":"low","exploited":false,"published_at":"2025-12-05T17:16:05.163+00:00","url":"https://junglewise.ai/threats/cve-2025-66546-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-4-7"},{"cve":"CVE-2025-66511","cvss":4.8,"epss":0.003,"slug":"cve-2025-66511-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-6-0-3","title":"Nextcloud Calendar is a calendar app for Nextcloud. Prior to 6.0.3, the Calendar app generates participant tokens for…","severity":"medium","exploited":false,"published_at":"2025-12-05T17:16:04.797+00:00","url":"https://junglewise.ai/threats/cve-2025-66511-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-6-0-3"}],"weekly":[{"week":"2026-08-17","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-08-24","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-08-31","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-09-07","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-09-14","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-09-21","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-09-28","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-10-05","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-10-12","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-10-19","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-10-26","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-11-02","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-11-09","critical":0,"exploited":0,"vulnerabilities":0}],"related":[{"name":"Nextcloud Server","slug":"nextcloud-server","vulnerabilities":14,"url":"https://junglewise.ai/threats/technologies/nextcloud-server"},{"name":"Nextcloud Enterprise Server","slug":"nextcloud-enterprise-server","vulnerabilities":7,"url":"https://junglewise.ai/threats/technologies/nextcloud-enterprise-server"},{"name":"Nextcloud Tables","slug":"tables","vulnerabilities":5,"url":"https://junglewise.ai/threats/technologies/tables"},{"name":"Nextcloud Approval","slug":"approval","vulnerabilities":4,"url":"https://junglewise.ai/threats/technologies/approval"},{"name":"Nextcloud Forms","slug":"forms","vulnerabilities":4,"url":"https://junglewise.ai/threats/technologies/forms"},{"name":"Nextcloud User OIDC","slug":"user-oidc","vulnerabilities":3,"url":"https://junglewise.ai/threats/technologies/user-oidc"}],"technology":{"hub":true,"name":"Nextcloud Calendar","slug":"calendar","vendor":{"hub":true,"name":"Nextcloud","slug":"nextcloud","url":"https://junglewise.ai/threats/vendors/nextcloud"},"aliases":[],"category":"application","homepage":"https://nextcloud.com/calendar/","repo_url":"https://github.com/nextcloud/calendar","description":"A calendar and scheduling application integrated into the Nextcloud platform.","url":"https://junglewise.ai/threats/technologies/calendar"},"most_severe":[{"cve":"CVE-2025-66550","cvss":5.7,"epss":0.0034,"slug":"cve-2025-66550-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-4-7","title":"Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.17 and 5.2.4, when a malicious user creates a…","severity":"medium","exploited":false,"published_at":"2025-12-05T17:16:05.5+00:00","url":"https://junglewise.ai/threats/cve-2025-66550-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-4-7"},{"cve":"CVE-2025-66511","cvss":4.8,"epss":0.003,"slug":"cve-2025-66511-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-6-0-3","title":"Nextcloud Calendar is a calendar app for Nextcloud. Prior to 6.0.3, the Calendar app generates participant tokens for…","severity":"medium","exploited":false,"published_at":"2025-12-05T17:16:04.797+00:00","url":"https://junglewise.ai/threats/cve-2025-66511-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-6-0-3"},{"cve":"CVE-2026-45286","cvss":4.3,"slug":"cve-2026-45286-nextcloud-calendar-user-enumeration-via-attendee-suggestion","title":"Nextcloud Calendar user enumeration via attendee suggestion endpoint","severity":"medium","exploited":false,"published_at":"2026-06-01T19:16:50.957+00:00","url":"https://junglewise.ai/threats/cve-2026-45286-nextcloud-calendar-user-enumeration-via-attendee-suggestion"},{"cve":"CVE-2025-66546","cvss":3.3,"epss":0.0014,"slug":"cve-2025-66546-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-4-7","title":"Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.19, 5.5.6, and 6.0.1, the calendar app allowed…","severity":"low","exploited":false,"published_at":"2025-12-05T17:16:05.163+00:00","url":"https://junglewise.ai/threats/cve-2025-66546-nextcloud-calendar-is-a-calendar-app-for-nextcloud-prior-to-4-7"}],"generated_at":"2026-11-09T03:07:00.176479+00:00"}