{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-66550","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2025-12-04T15:57:22.034Z","datePublished":"2025-12-05T16:56:44.680Z","dateUpdated":"2025-12-05T18:41:24.347Z"},"containers":{"cna":{"title":"Nextcloud Calendar attachments of local files are offered to downloaded","problemTypes":[{"descriptions":[{"cweId":"CWE-241","lang":"en","description":"CWE-241: Improper Handling of Unexpected Data Type","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.7,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f29c-ppmv-8mcv","tags":["x_refsource_CONFIRM"],"url":"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f29c-ppmv-8mcv"},{"name":"https://github.com/nextcloud/calendar/pull/6971","tags":["x_refsource_MISC"],"url":"https://github.com/nextcloud/calendar/pull/6971"},{"name":"https://github.com/nextcloud/calendar/commit/63a6c398db01391eb9fd5297a0d4c3d6e614f769","tags":["x_refsource_MISC"],"url":"https://github.com/nextcloud/calendar/commit/63a6c398db01391eb9fd5297a0d4c3d6e614f769"},{"name":"https://hackerone.com/reports/3112033","tags":["x_refsource_MISC"],"url":"https://hackerone.com/reports/3112033"}],"affected":[{"vendor":"nextcloud","product":"security-advisories","versions":[{"version":">= 5.0.0-rc.1, < 5.2.4","status":"affected"},{"version":"< 4.7.17","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2025-12-05T16:56:44.680Z"},"descriptions":[{"lang":"en","value":"Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.17 and 5.2.4, when a malicious user creates a calendar event with a crafted attachment that links to a download link of a file on the same Nextcloud server, the file would be downloaded without the user confirming the action. This vulnerability is fixed in 4.7.17 and 5.2.4."}],"source":{"advisory":"GHSA-f29c-ppmv-8mcv","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2025-12-05T18:37:20.458733Z","id":"CVE-2025-66550","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":"2025-12-05T18:41:24.347Z"}}]}}