Stored Cross-Site Scripting Vulnerability in Auto Thumbnail Plugin for WordPress
CVE-2026-8899

6.4MEDIUM

Key Information:

Vendor

WordPress
Status
Auto Thumbnails
Vendor
CVE Published:
27 May 2026

What is CVE-2026-8899?

The Auto Thumbnail plugin for WordPress is affected by a Stored Cross-Site Scripting vulnerability through the 'thumbnails' shortcode. This issue arises from inadequate input sanitization and output escaping on the 'width' and 'height' attributes within the athn_thumbnails() function. As a result, authorized attackers with contributor-level access can insert malicious web scripts into pages. These scripts execute when users access those compromised pages, posing risks to site visitors.

Affected Version(s)

Auto Thumbnails 0 <= 1.0

References

https://www.wordfence.com/threat-intel/vulnerabilities/id...
https://plugins.trac.wordpress.org/browser/automatic-thum...
https://plugins.trac.wordpress.org/browser/automatic-thum...

CVSS V3.1

Score:
6.4
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Gilang Asra Bilhadi
.