iCal export header/line-break injection hardening in iCal generator

The Events Calendar 6.16.4.1 (released June 19, 2026) hardens the iCalendar export feed against header injection and line-break injection. Prior to this fix, the plugin wrote unsanitized values into HTTP response headers and iCal VCALENDAR header fields: the Content-Disposition filename came directly from get_file_name() without sanitization, and the X-WR-CALNAME and X-ORIGINAL-URL fields embedded the unescaped site name/URL (filterable via tribe_ical_feed_calname). An attacker who could influence the site name or the calname filter value could inject CRLF sequences to add arbitrary HTTP headers or spoof iCal fields in the exported .ics file. The fix applies sanitize_file_name() to the Content-Disposition filename, esc_url_raw() to the site URL, and sanitize_text_field() to the calendar name before embedding them in HTTP headers and iCal output. A non-security companion change makes DTSTAMP deterministic (tied to event modified time rather than wall-clock).

This vulnerability affects the following application versions:

• The Events Calendar 5.0.0
• The Events Calendar 5.0.0.1
• The Events Calendar 5.0.0.3
• The Events Calendar 5.0.1.1
• The Events Calendar 5.0.1.2
• The Events Calendar 5.0.2
• The Events Calendar 5.0.2.2
• The Events Calendar 5.0.3.3
• The Events Calendar 5.1.0.1
• The Events Calendar 5.1.0.2
• The Events Calendar 5.1.1.1
• The Events Calendar 5.1.1.2
• The Events Calendar 5.1.2.1
• The Events Calendar 5.1.3
• The Events Calendar 5.1.3.1
• The Events Calendar 5.1.4
• The Events Calendar 5.1.4.1
• The Events Calendar 5.1.5
• The Events Calendar 5.1.5.1
• The Events Calendar 5.1.6
• The Events Calendar 5.1.6.1
• The Events Calendar 5.2.0
• The Events Calendar 5.2.0.1
• The Events Calendar 5.2.1
• The Events Calendar 5.2.1.1
• The Events Calendar 5.2.1.2
• The Events Calendar 5.3.0
• The Events Calendar 5.3.0.1
• The Events Calendar 5.3.1
• The Events Calendar 5.3.1.1
• The Events Calendar 5.3.1.2
• The Events Calendar 5.3.2
• The Events Calendar 5.3.2.1
• The Events Calendar 5.3.2.2
• The Events Calendar 5.4.0
• The Events Calendar 5.4.0.1
• The Events Calendar 5.4.0.2
• The Events Calendar 5.4.0.3
• The Events Calendar 5.5.0
• The Events Calendar 5.5.0.1
• The Events Calendar 5.5.0.2
• The Events Calendar 5.6.0
• The Events Calendar 5.7.0
• The Events Calendar 5.7.1
• The Events Calendar 5.8.0
• The Events Calendar 5.8.2
• The Events Calendar 5.9.0
• The Events Calendar 5.9.1
• The Events Calendar 5.9.2
• The Events Calendar 5.10.0
• The Events Calendar 5.10.1
• The Events Calendar 5.11.0
• The Events Calendar 5.12.0
• The Events Calendar 5.12.2
• The Events Calendar 5.12.3
• The Events Calendar 5.12.4
• The Events Calendar 5.13.0
• The Events Calendar 5.14.0
• The Events Calendar 5.14.0.1
• The Events Calendar 5.14.0.2
• The Events Calendar 5.14.0.3
• The Events Calendar 5.14.0.4
• The Events Calendar 5.14.1
• The Events Calendar 5.14.2
• The Events Calendar 5.14.2.1
• The Events Calendar 5.15.0
• The Events Calendar 5.15.0.1
• The Events Calendar 5.16.0
• The Events Calendar 5.16.1
• The Events Calendar 5.16.1.1
• The Events Calendar 5.16.2
• The Events Calendar 5.16.2.1
• The Events Calendar 5.16.3
• The Events Calendar 5.16.3.1
• The Events Calendar 5.16.4
• The Events Calendar 5.16.4.1
• The Events Calendar 6.0.0
• The Events Calendar 6.0.0.1
• The Events Calendar 6.0.1
• The Events Calendar 6.0.1.1
• The Events Calendar 6.0.2
• The Events Calendar 6.0.3
• The Events Calendar 6.0.3.1
• The Events Calendar 6.0.4
• The Events Calendar 6.0.5
• The Events Calendar 6.0.6
• The Events Calendar 6.0.6.1
• The Events Calendar 6.0.6.2
• The Events Calendar 6.0.7
• The Events Calendar 6.0.7.1
• The Events Calendar 6.0.8
• The Events Calendar 6.0.9
• The Events Calendar 6.0.10
• The Events Calendar 6.0.11
• The Events Calendar 6.0.12
• The Events Calendar 6.0.13
• The Events Calendar 6.0.13.1
• The Events Calendar 6.1.0
• The Events Calendar 6.1.0.1
• The Events Calendar 6.1.0.2
• The Events Calendar 6.1.1
• The Events Calendar 6.1.2
• The Events Calendar 6.1.2.1
• The Events Calendar 6.1.2.2
• The Events Calendar 6.1.3
• The Events Calendar 6.1.4
• The Events Calendar 6.2.0
• The Events Calendar 6.2.0.1
• The Events Calendar 6.2.1
• The Events Calendar 6.2.2
• The Events Calendar 6.2.2.1
• The Events Calendar 6.2.3
• The Events Calendar 6.2.3.1
• The Events Calendar 6.2.3.2
• The Events Calendar 6.2.4
• The Events Calendar 6.2.5
• The Events Calendar 6.2.6
• The Events Calendar 6.2.6.1
• The Events Calendar 6.2.7
• The Events Calendar 6.2.8
• The Events Calendar 6.2.8.1
• The Events Calendar 6.2.8.2
• The Events Calendar 6.3.0
• The Events Calendar 6.3.1
• The Events Calendar 6.3.3
• The Events Calendar 6.3.3.1
• The Events Calendar 6.3.4
• The Events Calendar 6.3.5
• The Events Calendar 6.3.6
• The Events Calendar 6.3.7
• The Events Calendar 6.4.0
• The Events Calendar 6.4.0.1
• The Events Calendar 6.5.0
• The Events Calendar 6.5.0.1
• The Events Calendar 6.5.1
• The Events Calendar 6.5.1.1
• The Events Calendar 6.5.1.2
• The Events Calendar 6.5.1.3
• The Events Calendar 6.5.1.4
• The Events Calendar 6.5.1.5
• The Events Calendar 6.5.1.6
• The Events Calendar 6.5.2
• The Events Calendar 6.6.0
• The Events Calendar 6.6.0.1
• The Events Calendar 6.6.0.2
• The Events Calendar 6.6.1
• The Events Calendar 6.6.2
• The Events Calendar 6.6.3
• The Events Calendar 6.6.4
• The Events Calendar 6.6.4.1
• The Events Calendar 6.6.4.2
• The Events Calendar 6.7.0
• The Events Calendar 6.7.1
• The Events Calendar 6.8.0
• The Events Calendar 6.8.1
• The Events Calendar 6.8.2
• The Events Calendar 6.8.2.1
• The Events Calendar 6.9.0
• The Events Calendar 6.9.1
• The Events Calendar 6.10.0
• The Events Calendar 6.10.1
• The Events Calendar 6.10.3
• The Events Calendar 6.11.0.1
• The Events Calendar 6.11.1
• The Events Calendar 6.11.2
• The Events Calendar 6.11.2.1
• The Events Calendar 6.13.0
• The Events Calendar 6.13.1
• The Events Calendar 6.13.2.1
• The Events Calendar 6.14.0
• The Events Calendar 6.14.1
• The Events Calendar 6.14.2
• The Events Calendar 6.15.0
• The Events Calendar 6.15.0.1
• The Events Calendar 6.15.1
• The Events Calendar 6.15.1.1
• The Events Calendar 6.15.2
• The Events Calendar 6.15.3
• The Events Calendar 6.15.4
• The Events Calendar 6.15.5
• The Events Calendar 6.15.6
• The Events Calendar 6.15.8
• The Events Calendar 6.15.9
• The Events Calendar 6.15.10
• The Events Calendar 6.15.12
• The Events Calendar 6.15.12.1
• The Events Calendar 6.15.12.2
• The Events Calendar 6.15.13
• The Events Calendar 6.15.13.1
• The Events Calendar 6.15.14
• The Events Calendar 6.15.15
• The Events Calendar 6.15.16
• The Events Calendar 6.15.17.1
• The Events Calendar 6.15.18
• The Events Calendar 6.15.19
• The Events Calendar 6.15.20
• The Events Calendar 6.16.0
• The Events Calendar 6.16.1
• The Events Calendar 6.16.2
• The Events Calendar 6.16.3
• The Events Calendar 6.16.4
• The Events Calendar 6.16.4.1