{“lastseen”:””,”description”:”Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, with the knowledge of other users\u2019 principal URL an attacker could possibly send a request to gain full access to their calendar. Therefore, the attacker must be an authenticated user. This is because of improper authorization controls in the backend of the calendar. If the attacker had access to the calendar, they would be able to view and modify it. It is recommended that the Nextcloud Server is upgraded to 33.0.3 or 32.0.9. It is recommended that the Nextcloud Enterprise Server is upgraded to 33.0.3, 32.0.9, 31.0.14.5, 30.0.17.9, 29.0.16.16, 28.0.14.17, 27.1.11.26, 26.0.13.26, 25.0.13.29, 24.0.12.34, 23.0.12.35, 22.2.10.39, or 21.0.9.23″,”published”:”2026-06-01T16:52:57.245Z”,”modified”:”2026-06-01T16:52:57.245Z”,”type”:”cve”,”title”:”Nextcloud: Cross-Account Calendar Takeover via Unauthorized Group-Member-Set Update”,”source”:”GitHub_M”,”references”:”https:\/\/github.com\/nextcloud\/security-advisories\/security\/advisories\/GHSA-hrrv-mp25-26vv\\nhttps:\/\/github.com\/nextcloud\/server\/pull\/59962\\nhttps:\/\/hackerone.com\/reports\/3545964″,”id”:”CVE-2026-45281″,”bulletinFamily”:””,”cwe”:[“CWE-639″],”cvelist”:null,”sourceData”:”nextcloud security-advisories \\u003e= 32.0.0, \\u003c 32.0.9\\nnextcloud security-advisories \\u003e= 33.0.0, \\u003c 33.0.3″,”sourceHref”:””,”cvss”:{“score”:8.1,”severity”:”HIGH”,”vector”:”CVSS:3.1\/AV:N\/AC:L\/PR:L\/UI:N\/S:U\/C:H\/I:H\/A:N”,”version”:”3.1″},”cvss2″:{},”cvss3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””,”cvssV3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””}},”href”:””,”category_name”:”CVE”,”post_link”:””,”product”:”security-advisories”,”version”:”\\u003e= 32.0.0, \\u003c 32.0.9″,”vendor”:”nextcloud”,”ai_description”:””,”ai_severity”:””,”ai_vendor”:””,”ai_product”:””,”ai_version”:””,”ai_score”:0}<\/p>\n","protected":false},"excerpt":{"rendered":"
{“lastseen”:””,”description”:”Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, with the knowledge…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[6,8,52,12,15,13,7,11,5],"class_list":["post-58980","post","type-post","status-publish","format-standard","hentry","category-category_cve","tag-cve","tag-cvss","tag-cvss-81","tag-exploit","tag-high","tag-news","tag-security","tag-tapic","tag-vulnerability"],"yoast_head":"\n