Vulnerability · Published Jul 11, 2026 · Assigned by Wordfence

CVE-2026-5743Mixed Media Gallery Blocks <= 3.3.3.1 - Authenticated (Author+) Stored Cross-Site Scripting via sliderMaxHeight Block Attribute

Medium 6.4

In plain English

A medium-severity cross-site scripting in SimpLy Gallery from gallerycreator. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities).

Severity (CVSS 3.1)6.4Medium

Exploit odds (30 days)0.4%top 60.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

The SimpLy Gallery Block & Lightbox plugin for WordPress is vulnerable to Stored Cross-Site Scripting via block attributes in all versions up to, and including, 3.3.3.2. This is due to insufficient input sanitization and output escaping on the sliderMaxHeight block attribute in the pgc_sgb_render_callback() function. The vulnerability exists because the pgc_sgb_sanitize_custom_css() function uses a flawed regex pattern that only removes event handlers with quoted values (e.g., onfocus="alert()") but fails to catch unquoted event handlers (e.g., onfocus=alert(document.cookie)), allowing the malicious code to bypass sanitization. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages via block attributes that will execute whenever a user accesses an injected page.

Affected products (as reported)

Vendor	Product	Versions
gallerycreator	SimpLy Gallery	0 – through 3.3.3.1

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

In plain English

Official description

Affected products (as reported)

References