# Off-Canvas Sidebars & Menus (Slidebars) <= 0.5.9 - Authenticated (Contributor+) Stored Cross-Site Scripting via ocs_trigger Shortcode

- **ID:** WPSEC-2026-1437
- **Plugin:** Off-Canvas Sidebars & Menus (Slidebars) (`off-canvas-sidebars`), https://wordpress.org/plugins/off-canvas-sidebars/
- **Affected versions:** all versions before 0.5.9.1
- **Fixed in:** 0.5.9.1 (Update to 0.5.9.1 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 2026-10-22)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/off-canvas-sidebars
- **Fix released:** 2026-10-21
- **Published:** 2026-10-22
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1437/

## Description

The Off-Canvas Sidebars & Menus (Slidebars) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'ocs_trigger' shortcode in all versions up to, and including, 0.5.9. This is due to insufficient validation of the shortcode's 'element' and 'attr' attributes. Any element name made of word characters that is not on a short blocklist is accepted (for example iframe), and attribute values are escaped and screened for a few characters but never checked for script URL schemes such as javascript:. 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-2026-1437/
- https://plugins.svn.wordpress.org/off-canvas-sidebars/tags/0.5.9.1/
- https://wordpress.org/plugins/off-canvas-sidebars/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1437/

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.