{
    "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"
                }
            }
        ]
    }
}