CVE-2026-5743
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or โ if you've already worked around this in production โ publish your fix to the community-verified tier.
โ Propose a mitigation on Community โ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L122
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L142
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L151
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L95
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L122
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L142
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L151
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L95
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3581386%40simply-gallery-block&new=3581386%40simply-gallery-block
- https://www.wordfence.com/threat-intel/vulnerabilities/id/29b1984d-e6da-49d5-8b40-cdf2f1bcc1bb?source=cve
CWEs
CWE-79
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.