CVE-2026-109234: Meow Lightbox stored cross-site scripting (XSS) vulnerability
high 7.2 published 2026-10-31 · updated 2026-11-02
- Affected versions
- 5.6.4 and older
- Fixed in
- 5.6.5 *
- Latest version
- 5.6.5
- Severity
- High · CVSS 7.2
- Active installs
- 10,000+
- 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: None. No account or login is needed.
CVSS vector (score by Wordfence): CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
What to do now
- Update Meow Lightbox to 5.6.5 or newer: 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 Meow Lightbox issue.
With WP-CLI:
wp plugin get meow-lightbox --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 Meow Lightbox plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'post_content (bbPress reply body)' parameter in all versions up to, and including, 5.6.4 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the administrator to have enabled Output Buffering, the HtmlDomParser engine, and Aggressive Resolve, as well as a stored-HTML submission surface (such as bbPress anonymous replies) whose kses allow-list preserves img attributes; given these preconditions, a one-shot unauthenticated submission can execute arbitrary JavaScript in the context of any user who views the affected page.
References
- NVD CVE-2026-109234 nvd.nist.gov
- Wordfence advisory www.wordfence.com
- Code change (fix) plugins.trac.wordpress.org
- Plugin source plugins.trac.wordpress.org
Related
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/meow-lightbox (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.