CVE-2026-109975: Cozy Blocks stored cross-site scripting (XSS) vulnerability

medium 6.4 published 2026-10-28 · updated 2026-10-29

Affected versions: 2.2.27 and older
Fixed in: 2.2.28 *
Latest version: 2.2.29
Severity: Medium · CVSS 6.4
Active installs: 6,000+
Type: Stored cross-site scripting (XSS)

* The source does not name a fixed version; this is the first wordpress.org release after the last affected version.

What an attacker needs

Access: A logged-in account with Contributor-level access or higher.

CVSS vector (score by Wordfence): CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

What to do now

Update Cozy Blocks to 2.2.28 or newer (the latest is 2.2.29): Dashboard → Updates, or Plugins → “update now”.
If you cannot update right away, deactivate it until you can.
Turn on auto-updates for it: Plugins → “Enable auto-updates” on its row.
Not sure which version you run? Check your version against every known Cozy Blocks issue. With WP-CLI: wp plugin get cozy-addons --field=version.
If you ran an affected version and something looks off (new admin users, spam pages, redirects), run the free scan below.

The advisory

The Cozy Blocks – Website Builder for WordPress Block Editor | Gutenberg Blocks, Patterns & Templates plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'content (block attribute icon.view / icon.layout / icon.gap)' parameter in all versions up to, and including, 2.2.27 due to insufficient input sanitization and output escaping. 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. Although wp_kses_post is applied on save, it does not neutralize a quote-only attribute-breakout payload containing no '<' character, leaving the block comment and its decoded JSON attributes intact and exploitable at render time.

Description from the CVE record, published by Wordfence (the CVE Numbering Authority), via the NVD entry for CVE-2026-109975.

References

NVD CVE-2026-109975 nvd.nist.gov
Wordfence advisory www.wordfence.com
Code change (fix) plugins.trac.wordpress.org
Plugin source plugins.trac.wordpress.org

Ran an affected version? Check your site for signs of a hack

The free scan reads the public side of your site and looks for spam pages, hidden redirects, injected scripts and blacklist entries. No login, no install, about a minute.

Where this data comes from

CVE record, score and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
Versions and install counts: wordpress.org/plugins/cozy-addons (Plugins API), fetched 2026-11-04.
The summary, “what an attacker needs” and “what to do” sections are our plain-English reading of the record and the plugin's release history; the quoted description is the record's own text. Spot an error? Email Daniel.