CVE-2026-109936: Otter Blocks stored cross-site scripting (XSS) vulnerability
high 7.5 published 2026-10-23
- Affected versions
- older than 3.2.8
- Fixed in
- 3.2.8
- Latest version
- 3.2.8
- Severity
- High · CVSS 7.5
- Active installs
- 300,000+
- Type
- Stored cross-site scripting (XSS)
What an attacker needs
- Access: None. No account or login is needed.
- Interaction: It also needs someone on the site (often an admin) to click a link, open a page or submit a form the attacker prepared.
CVSS vector (score by CISA ADP): CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
What to do now
- Update Otter Blocks to 3.2.8 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 Otter Blocks issue.
With WP-CLI:
wp plugin get otter-blocks --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 Otter Blocks WordPress plugin before 3.2.8 does not correctly bound a pattern it uses to rewrite its dynamic-content tokens while rendering blocks, so the pattern can consume the quote that closes an HTML attribute and pull adjacent unescaped data into the markup as new attributes. This allows unauthenticated users to achieve stored Cross-Site Scripting that executes in the browser of any visitor who views an affected page, including a logged-in administrator.
References
- NVD CVE-2026-109936 nvd.nist.gov
- WPScan advisory wpscan.com
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/otter-blocks (Plugins API), fetched 2026-11-01.
- 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.