CVE-2026-55247

{"id": "CVE-2026-55247", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55247", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-31T18:48:16.302616Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "LOW"}, "impactScore": 5.3, "exploitabilityScore": 3.1}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "plone", "product": "plone.app.event", "versions": [{"status": "affected", "version": "< 5.2.4"}, {"status": "affected", "version": ">= 6.0.0, < 6.0.1"}]}]}], "published": "2026-08-28T20:18:26.890", "references": [{"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", "source": "security-advisories@github.com"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-400"}]}], "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."}], "lastModified": "2026-09-09T21:09:13.080", "sourceIdentifier": "security-advisories@github.com"}