CVE-2026-5743
Mixed Media Gallery Blocks <= 3.3.3.1 - Authenticated (Author+) Stored Cross-Site Scripting via sliderMaxHeight Block Attribute
- Published
- Updated
- Reserved
- Assigned by
- Wordfence
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| WordfenceCNA (assigner) | 3.1 | Medium6.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
| NVDNVD · Deferred | 3.1 | Medium6.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.45% · top 61% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.4.
Weakness
Affected products
gallerycreator · SimpLy Gallery
- affected ≤ 3.3.3.1
References (10)
- https://www.wordfence.com/threat-intel/vulnerabilities/id/29b1984d-e6da-49d5-8b40-cdf2f1bcc1bb?source=cve (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L95 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L95 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L122 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L122 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L142 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L142 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/trunk/blocks/init.php#L151 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L151 (opens in a new tab)
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3581386%40simply-gallery-block&new=3581386%40simply-gallery-block (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-5743)Record last updated .