CVE-2026-8899
Auto Thumbnails <= 1.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes
CVSS Score
6.4
EPSS Score
0.0%
EPSS Percentile
0th
The Auto Thumbnail plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'thumbnails' shortcode in all versions up to, and including, 1.0. This is due to insufficient input sanitization and output escaping on the shortcode's 'width' and 'height' attributes in the athn_thumbnails() function, which are concatenated directly into an HTML <img> tag. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
| CWE | CWE-79 |
| Vendor | gapgag55 |
| Product | auto thumbnails |
| Published | May 27, 2026 |
| Last Updated | May 27, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Affected Versions
gapgag55 / Auto Thumbnails
0 ≤ 1.0
References
wordfence.com: https://www.wordfence.com/threat-intel/vulnerabilities/id/f0cc349a-96f9-4b11-a0b4-28bc4ccc022c?source=cve plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/automatic-thumbnail/tags/1.0/index.php#L34 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/automatic-thumbnail/tags/1.0/index.php#L13
Credits
Gilang Asra Bilhadi