# Open Source Event Calendar <= 1.2.0 - Authenticated (Author+) Stored Cross-Site Scripting via Parent Event Title

- **ID:** WPSEC-2026-2412
- **Plugin:** Open Source Event Calendar (`open-source-event-calendar`), https://wordpress.org/plugins/open-source-event-calendar/
- **Affected versions:** all versions before 1.2.1
- **Fixed in:** 1.2.1 (Update to 1.2.1 or later.)
- **Severity:** Medium 6.4 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-11-03)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/open-source-event-calendar
- **Fix released:** 2026-11-02
- **Published:** 2026-11-03
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2412/

## Description

The Open Source Event Calendar plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the parent event title, which is shown in the 'Base Event' row action of the admin event list, in all versions up to, and including, 1.2.0. This is due to insufficient output escaping of the title inside an HTML title attribute. This makes it possible for authenticated attackers with author-level access and above (or the plugin's Event Contributor role) to inject arbitrary web scripts. The scripts run whenever an administrator or editor views the event list.

## References

- https://wpsec.com/vuln/WPSEC-2026-2412/
- https://plugins.svn.wordpress.org/open-source-event-calendar/tags/1.2.1/
- https://wordpress.org/plugins/open-source-event-calendar/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2412/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.