---
id: CVE-2026-5743
title: >-
  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
summary: >-
  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 …
severity: medium
cvss: 6.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
published: '2026-07-11'
updated: '2026-07-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-5743'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L122
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L142
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L151
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L95
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L122
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L142
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L151
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L95
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset?reponame=&old=3581386%40simply-gallery-block&new=3581386%40simply-gallery-block
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/29b1984d-e6da-49d5-8b40-cdf2f1bcc1bb?source=cve
    label: security@wordfence.com
tags:
  - nvd
epss: 0.0045
epssPercentile: 0.38449
ingestedAt: '2026-07-11T22:16:01.235Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.