{"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"}}}}

{}

{"affected": [{"affectedData": [{"product": "icalendar", "vendor": "collective", "versions": [{"status": "affected", "version": ">= 6.1.0, < 7.2.2"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "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."}], "id": "CVE-2026-77399", "lastModified": "2026-09-22T19:16:51.443", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 2.8, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-09-22T19:16:51.443", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/collective/icalendar/commit/157f85137c65565a308bbcf4fdcc7d8ebce01267"}, {"source": "security-advisories@github.com", "url": "https://github.com/collective/icalendar/commit/cddd37226adbc52cca52a399f61d38a378221219"}, {"source": "security-advisories@github.com", "url": "https://github.com/collective/icalendar/pull/1571"}, {"source": "security-advisories@github.com", "url": "https://github.com/collective/icalendar/releases/tag/v7.2.2"}, {"source": "security-advisories@github.com", "url": "https://github.com/collective/icalendar/security/advisories/GHSA-qjcq-q7h7-r74v"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}, {"lang": "en", "value": "CWE-834"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.1.0,7.2.2)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "icalendar", "source": "cna", "vendor": "collective"}, "product": "icalendar", "vendor": "collective"}], "created": "2026-09-22T21:15:06.942644+00:00", "updated": "2026-09-22T21:15:07.340011+00:00", "vendors": ["collective", "collective$PRODUCT$icalendar"]}