CVE-2026-108587: 10Web Booster arbitrary file upload vulnerability
critical 9.8 published 2026-10-15
- Affected versions
- 2.34.10 and older
- Fixed in
- 2.34.11 *
- Latest version
- 2.34.11
- Severity
- Critical · CVSS 9.8
- Active installs
- 60,000+
- Type
- Arbitrary file upload
* 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:U/C:H/I:H/A:H
What to do now
- Update 10Web Booster to 2.34.11 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 10Web Booster issue.
With WP-CLI:
wp plugin get tenweb-speed-optimizer --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 10Web Booster – Website speed optimization, Cache & Page Speed optimizer plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.34.10 via the compressCustom function. This is due to missing file type validation and extension filtering on the page_id parameter, combined with a world-readable leaked nonce that bypasses authentication checks. This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible. This exploit chain requires obtaining the plugin's REST nonce (tenwebio_rest), which is automatically serialized to a world-readable file under wp-content/uploads/ whenever a bulk optimisation batch pauses; because the nonce is generated in a cron/loopback context with a user ID of 0, it is valid for unauthenticated visitors.
References
- NVD CVE-2026-108587 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/tenweb-speed-optimizer (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.