# Strong Testimonials <= 3.3.17 - Unauthenticated Arbitrary Shortcode Execution via Testimonial Submission Form

- **ID:** WPSEC-2026-2873
- **Plugin:** Strong Testimonials (`strong-testimonials`), https://wordpress.org/plugins/strong-testimonials/
- **Affected versions:** all versions before 3.3.18
- **Fixed in:** 3.3.18 (Update to 3.3.18 or later.)
- **Severity:** Medium 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N)
- **Weakness:** CWE-94
- **Usage among sites WPSec scans:** plugin Medium, affected versions Medium (as of 2026-11-12)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/strong-testimonials
- **Fix released:** 2026-11-10
- **Published:** 2026-11-12
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2873/

## Description

The Strong Testimonials plugin for WordPress is vulnerable to arbitrary shortcode execution via the public testimonial submission form in all versions up to, and including, 3.3.17. This is due to the plugin storing square brackets unencoded in the submitted testimonial text and custom field values, and then showing those values in output that WordPress runs through do_shortcode, such as the 'the_content' filter on the single testimonial page. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes when the submitted testimonial is displayed. With the default moderation setting, the testimonial must first be published.

## References

- https://wpsec.com/vuln/WPSEC-2026-2873/
- https://plugins.svn.wordpress.org/strong-testimonials/tags/3.3.18/
- https://wordpress.org/plugins/strong-testimonials/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2873/

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.