CVE-2008-5840: PHP iCalendar 2.24 and earlier allows remote attackers to bypass authentication by setting the phpicalendar...

Security readout for executives and security teams

CVE-2008-5840 is an authentication bypass in PHP iCalendar 2.24 and earlier. An attacker could access protected calendar functionality by manipulating client-controlled cookies. Business impact depends on whether the application still exists and whether calendars expose sensitive schedules, internal contacts, or operational details. Exposure is likely limited to organizations still running PHP iCalendar 2.24 or earlier. Risk rises for internet-facing deployments or intranet calendars containing sensitive business, staff, or operational scheduling data. The affected metadata is incomplete, so asset and version confirmation is required. Treat as a targeted legacy-application cleanup item. Prioritize quickly if PHP iCalendar is internet-facing or protects sensitive calendars. If no deployment exists, record as not applicable. Mitigation focus: Identify any PHP iCalendar deployments and confirm versions.; Restrict access to trusted networks until vendor guidance is confirmed.; Check vendor or maintainer sources for upgrade or patch guidance..

Prepared

Jun 28, 2026, 11:41 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.