CVE-2026-9239: XSS (CVSS 6.4)

Description

The Meow Gallery plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Attachment Alt Text (aria-label attribute) in all versions up to, and including, 5.5.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The vulnerable code path is only reachable when a gallery item is rendered as a link (i.e., link_href is non-empty), and exploitation relies on the fact that WordPress's sanitize_text_field() strips angle-bracketed tags but preserves double quotes, allowing an attacker to break out of the aria-label attribute context and inject event-handler attributes such as onclick.

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CVSS v3.1 Score

6.4

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

EPSS — Exploit Prediction

0.0032

Probability of exploitation

0.25%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://plugins.trac.wordpress.org/browser/meow-gallery/tags/5.4.5/classes/core.php#L465 https://plugins.trac.wordpress.org/browser/meow-gallery/tags/5.4.5/classes/core.php#L469 https://plugins.trac.wordpress.org/browser/meow-gallery/tags/5.4.5/classes/run.php#L12 https://plugins.trac.wordpress.org/browser/meow-gallery/tags/5.4.9/classes/core.php#L465 https://plugins.trac.wordpress.org/browser/meow-gallery/tags/5.4.9/classes/core.php#L469 https://plugins.trac.wordpress.org/browser/meow-gallery/tags/5.4.9/classes/run.php#L12 https://plugins.trac.wordpress.org/changeset?old_path=/meow-gallery/tags/5.5.1&new_path=/meow-gallery/tags/5.5.2 https://www.wordfence.com/threat-intel/vulnerabilities/id/49afa739-83f0-4ad7-9e5e-d600f293b938?source=cve

Frequently Asked Questions

What is CVE-2026-9239? +

The Meow Gallery plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Attachment Alt Text (aria-label attribute) in all versions up to, and including, 5.5.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The vulnerable code path is only reachable when a gallery item is rendered as a link (i.e., link_href is non-empty), and exploitation relies on the fact that WordPress's sanitize_text_field() strips angle-bracketed tags but preserves double quotes, allowing an attacker to break out of the aria-label attribute context and inject event-handler attributes such as onclick. It has a CVSS v3.1 base score of 6.4 (MEDIUM).

How severe is CVE-2026-9239? +

CVE-2026-9239 has a CVSS v3.1 score of 6.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0032, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-9239? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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