CVE-2026-9239: Meow Gallery stored cross-site scripting (XSS) vulnerability
medium 6.4 published 2026-10-30
- Affected versions
- 5.5.1 and older
- Fixed in
- 5.5.2 *
- Latest version
- 5.5.8
- Severity
- Medium · CVSS 6.4
- 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: A logged-in account with Author-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 Meow Gallery to 5.5.2 or newer (the latest is 5.5.8): 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 Gallery issue.
With WP-CLI:
wp plugin get meow-gallery --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 Gallery plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Attachment Alt Text (aria-label attribute) in all versions up to, and including, 5.5.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The vulnerable code path is only reachable when a gallery item is rendered as a link (i.e., link_href is non-empty), and exploitation relies on the fact that WordPress's sanitize_text_field() strips angle-bracketed tags but preserves double quotes, allowing an attacker to break out of the aria-label attribute context and inject event-handler attributes such as onclick.
References
- NVD CVE-2026-9239 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-gallery (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.