{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55247","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-06-16T16:44:00.624Z","datePublished":"2026-08-28T18:59:01.212Z","dateUpdated":"2026-08-31T18:48:31.264Z"},"containers":{"cna":{"title":"plone.app.event: Denial of service via iCalendar import","problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":9.1,"baseSeverity":"CRITICAL","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H","version":"3.1"}}],"references":[{"name":"https://github.com/plone/plone.app.event/security/advisories/GHSA-r82h-mqw3-fc56","tags":["x_refsource_CONFIRM"],"url":"https://github.com/plone/plone.app.event/security/advisories/GHSA-r82h-mqw3-fc56"},{"name":"https://github.com/plone/plone.app.event/commit/1e3c83c15a24d1a789cdb012593505bc5620e28e","tags":["x_refsource_MISC"],"url":"https://github.com/plone/plone.app.event/commit/1e3c83c15a24d1a789cdb012593505bc5620e28e"},{"name":"https://github.com/plone/plone.app.event/commit/4de5eb3ea9e4f7f1781622e6d64fc086629d1437","tags":["x_refsource_MISC"],"url":"https://github.com/plone/plone.app.event/commit/4de5eb3ea9e4f7f1781622e6d64fc086629d1437"},{"name":"https://github.com/plone/plone.app.event/releases/tag/5.2.4","tags":["x_refsource_MISC"],"url":"https://github.com/plone/plone.app.event/releases/tag/5.2.4"},{"name":"https://github.com/plone/plone.app.event/releases/tag/6.0.1","tags":["x_refsource_MISC"],"url":"https://github.com/plone/plone.app.event/releases/tag/6.0.1"}],"affected":[{"vendor":"plone","product":"plone.app.event","versions":[{"version":"< 5.2.4","status":"affected"},{"version":">= 6.0.0, < 6.0.1","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-08-28T18:59:01.212Z"},"descriptions":[{"lang":"en","value":"plone.app.event provides the event content type for Plone. Prior to versions 5.2.4 and 6.0.1, the iCalendar import in src/plone/app/event/ical/importer.py accepts insufficiently restricted calendar and event URLs, does not adequately bound downloaded bytes or imported events, and commits work per event. A logged-in editor can make the server request internal network resources or local calendar files, exhaust resources and take the site offline, and store a malicious event URL that executes script in another user's browser. The fix restricts accepted URLs, applies MAXIMUM_ICAL_IMPORT_SIZE_BYTES and MAXIMUM_ICAL_IMPORT_EVENTS limits, uses transaction savepoints, and validates event URLs. This issue is fixed in versions 5.2.4 and 6.0.1."}],"source":{"advisory":"GHSA-r82h-mqw3-fc56","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-31T18:48:16.302616Z","id":"CVE-2026-55247","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":"2026-08-31T18:48:31.264Z"}}]}}