CVE-2026-100175: Postie stored cross-site scripting (XSS) vulnerability
medium 5.4 published 2026-10-28 · updated 2026-10-29
- Affected versions
- 1.9.87 and older
- Fixed in
- 1.9.88 *
- Latest version
- 1.9.88
- Severity
- Medium · CVSS 5.4
- 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: None. No account or login is needed.
CVSS vector (score by Wordfence): CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
What to do now
- Update Postie to 1.9.88 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 Postie issue.
With WP-CLI:
wp plugin get postie --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 Postie plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Email Body URL Autolink in all versions up to, and including, 1.9.87 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 is possible because the ?postie=get-mail endpoint is reachable by unauthenticated users with no capability check, and the email processing path removes WordPress's kses output filters before saving raw markup, allowing the unescaped href attribute value to be stored as post content.
References
- NVD CVE-2026-100175 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/postie (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.