# Subscribe to Comments <= 2.3.1 - Reflected Cross-Site Scripting via 'ref' Parameter

- **ID:** WPSEC-2026-0588
- **Plugin:** Subscribe to Comments (`subscribe-to-comments`), https://wordpress.org/plugins/subscribe-to-comments/
- **Affected versions:** all versions before 2.3.2
- **Fixed in:** 2.3.2 (Update to 2.3.2 or later.)
- **Severity:** Medium 6.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin Low, affected versions None seen (as of 2026-10-07)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/subscribe-to-comments
- **Fix released:** 2026-10-06
- **Published:** 2026-10-07
- **URL:** https://wpsec.com/vuln/WPSEC-2026-0588/

## Description

The Subscribe to Comments plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'ref' parameter of the subscription manager in all versions up to, and including, 2.3.1 due to insufficient input validation and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user, such as an administrator, into clicking a link.

## References

- https://wpsec.com/vuln/WPSEC-2026-0588/
- https://plugins.svn.wordpress.org/subscribe-to-comments/tags/2.3.2/
- https://wordpress.org/plugins/subscribe-to-comments/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-0588/

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.