{"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": "2026-08-28T18:59:01.212Z"}, "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"}}}}

{}

{"affected": [{"affectedData": [{"product": "plone.app.event", "vendor": "plone", "versions": [{"status": "affected", "version": "< 5.2.4"}, {"status": "affected", "version": ">= 6.0.0, < 6.0.1"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "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."}], "id": "CVE-2026-55247", "lastModified": "2026-08-28T20:18:26.890", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 3.1, "impactScore": 5.3, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-08-28T20:18:26.890", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/plone/plone.app.event/commit/1e3c83c15a24d1a789cdb012593505bc5620e28e"}, {"source": "security-advisories@github.com", "url": "https://github.com/plone/plone.app.event/commit/4de5eb3ea9e4f7f1781622e6d64fc086629d1437"}, {"source": "security-advisories@github.com", "url": "https://github.com/plone/plone.app.event/releases/tag/5.2.4"}, {"source": "security-advisories@github.com", "url": "https://github.com/plone/plone.app.event/releases/tag/6.0.1"}, {"source": "security-advisories@github.com", "url": "https://github.com/plone/plone.app.event/security/advisories/GHSA-r82h-mqw3-fc56"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"created": "2026-08-28T21:00:04.540164+00:00", "updated": "2026-08-28T21:00:04.540169+00:00", "vendors": []}