# Spectra Legacy – Gutenberg Blocks <= 2.20.5 - Authenticated (Contributor+) Stored Cross-Site Scripting via Counter Block 'data-counter' Attribute

- **ID:** WPSEC-2026-2457
- **Plugin:** Spectra Legacy – Gutenberg Blocks (`ultimate-addons-for-gutenberg`), https://wordpress.org/plugins/ultimate-addons-for-gutenberg/
- **Affected versions:** from 2.5.0 before 2.20.6
- **Fixed in:** 2.20.6 (Update to 2.20.6 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 High, affected versions High (as of 2026-11-04)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/ultimate-addons-for-gutenberg
- **Fix released:** 2026-11-03
- **Published:** 2026-11-04
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2457/

## Description

The Spectra Legacy – Gutenberg Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Counter block's 'data-counter' HTML attribute in all versions up to, and including, 2.20.5, due to the front-end counter script parsing options from that attribute in the saved post markup, letting them override the server-generated options, and passing the unsanitized thousand separator value to the CountUp library, which writes the formatted number with innerHTML. 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-2026-2457/
- https://plugins.svn.wordpress.org/ultimate-addons-for-gutenberg/tags/2.20.6/
- https://wordpress.org/plugins/ultimate-addons-for-gutenberg/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2457/

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.