# Otter Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE <= 3.2.9 - Authenticated (Contributor+) Stored Cross-Site Scripting via Dynamic Magic Tags in HTML Attributes

- **ID:** WPSEC-2026-2811
- **Plugin:** Otter Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE (`otter-blocks`), https://wordpress.org/plugins/otter-blocks/
- **Affected versions:** from 2.1.1 before 3.2.10
- **Fixed in:** 3.2.10 (Update to 3.2.10 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 Medium, affected versions Medium (as of 2026-11-10)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/otter-blocks
- **Fix released:** 2026-11-09
- **Published:** 2026-11-10
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2811/

## Description

The Otter Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Dynamic Content magic tags placed inside HTML attributes in all versions up to, and including, 3.2.9, due to resolved magic tag values being only attribute-escaped, with no protocol check on URL attributes, no style sanitization, and no removal of event-handler or srcdoc attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts (for example, a javascript: URL resolved into a link's href) in pages that will execute whenever a user accesses an injected page.

## References

- https://wpsec.com/vuln/WPSEC-2026-2811/
- https://plugins.svn.wordpress.org/otter-blocks/tags/3.2.10/
- https://wordpress.org/plugins/otter-blocks/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2811/

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.