# Event Organiser <= 3.12.10 - Authenticated (Contributor+) Stored Cross-Site Scripting via %event_thumbnail% Shortcode Template Tag

- **ID:** WPSEC-2026-1675
- **Plugin:** Event Organiser (`event-organiser`), https://wordpress.org/plugins/event-organiser/
- **Affected versions:** all versions before 3.12.11
- **Fixed in:** 3.12.11 (Update to 3.12.11 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 2026-10-27)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/event-organiser
- **Fix released:** 2026-10-25
- **Published:** 2026-10-26
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1675/

## Description

The Event Organiser plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the %event_thumbnail% template tag in the event list shortcode in all versions up to, and including, 3.12.10 due to insufficient input sanitization and output escaping on user-supplied image attributes, which are HTML-entity-decoded and passed into the thumbnail img tag. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

## References

- https://wpsec.com/vuln/WPSEC-2026-1675/
- https://plugins.svn.wordpress.org/event-organiser/tags/3.12.11/
- https://wordpress.org/plugins/event-organiser/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1675/

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.