{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-77399", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-08-20T19:55:27.023Z", "datePublished": "2026-09-22T18:58:56.647Z", "dateUpdated": "2026-09-22T18:58:56.647Z"}, "containers": {"cna": {"title": "icalendar: Denial of service via unbounded VALARM REPEAT expansion", "problemTypes": [{"descriptions": [{"cweId": "CWE-400", "lang": "en", "description": "CWE-400: Uncontrolled Resource Consumption", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-834", "lang": "en", "description": "CWE-834: Excessive Iteration", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/collective/icalendar/security/advisories/GHSA-qjcq-q7h7-r74v", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/collective/icalendar/security/advisories/GHSA-qjcq-q7h7-r74v"}, {"name": "https://github.com/collective/icalendar/pull/1571", "tags": ["x_refsource_MISC"], "url": "https://github.com/collective/icalendar/pull/1571"}, {"name": "https://github.com/collective/icalendar/commit/157f85137c65565a308bbcf4fdcc7d8ebce01267", "tags": ["x_refsource_MISC"], "url": "https://github.com/collective/icalendar/commit/157f85137c65565a308bbcf4fdcc7d8ebce01267"}, {"name": "https://github.com/collective/icalendar/commit/cddd37226adbc52cca52a399f61d38a378221219", "tags": ["x_refsource_MISC"], "url": "https://github.com/collective/icalendar/commit/cddd37226adbc52cca52a399f61d38a378221219"}, {"name": "https://github.com/collective/icalendar/releases/tag/v7.2.2", "tags": ["x_refsource_MISC"], "url": "https://github.com/collective/icalendar/releases/tag/v7.2.2"}], "affected": [{"vendor": "collective", "product": "icalendar", "versions": [{"version": ">= 6.1.0, < 7.2.2", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-22T18:58:56.647Z"}, "descriptions": [{"lang": "en", "value": "icalendar is an RFC 5545 compatible parser and generator of iCalendar files for Python. From 6.1.0 until 7.2.2, vInt.from_ical accepts an attacker-controlled VALARM REPEAT value and applications that request alarm times can eagerly expand it without an application-level limit. Alarms.times and Alarms.active reach the unbounded expansion in versions starting with 6.1.0, while Alarm.triggers adds a second affected path starting with 7.0.0. Parsing alone does not trigger the issue, but accessing these properties can consume excessive CPU time and heap memory and terminate or stall a service. This issue is fixed in version 7.2.2."}], "source": {"advisory": "GHSA-qjcq-q7h7-r74v", "discovery": "UNKNOWN"}}}}