# Blocks Animation <= 3.2.10 - Authenticated (Contributor+) CSS Injection via Custom Animation Delay and Speed Values

- **ID:** WPSEC-2026-3137
- **Plugin:** Blocks Animation: CSS Animations for Gutenberg Blocks (`blocks-animation`), https://wordpress.org/plugins/blocks-animation/
- **Affected versions:** from 2.5.0 before 3.2.11
- **Fixed in:** 3.2.11 (Update to 3.2.11 or later.)
- **Severity:** Medium 5.4 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N)
- **Weakness:** CWE-74
- **Usage among sites WPSec scans:** plugin Medium, affected versions Medium (as of 2026-11-14)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/blocks-animation
- **Fix released:** 2026-11-13
- **Published:** 2026-11-14
- **URL:** https://wpsec.com/vuln/WPSEC-2026-3137/

## Description

The Blocks Animation plugin for WordPress is vulnerable to CSS Injection via the custom animation delay and speed values in versions 2.5.0 up to, and including, 3.2.10. This is due to the front-end script reading the 'o-anim-value-delay-' and 'o-anim-value-speed-' class names of animated blocks and writing the remaining value, without validation, into a page-wide style element. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary CSS rules into pages that render the block, for example to hide or restyle page content, overlay the page with attacker-controlled links, or make visitors' browsers load external resources. It does not allow script execution.

## References

- https://wpsec.com/vuln/WPSEC-2026-3137/
- https://plugins.svn.wordpress.org/blocks-animation/tags/3.2.11/
- https://wordpress.org/plugins/blocks-animation/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-3137/

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.