CVE-2026-5743 json
Mixed Media Gallery Blocks <= 3.3.3.1 - Authenticated (Author+) Stored Cross-Site Scripting via sliderMaxHeight Block Attribute
published 2026-07-11 3 mo ago modified 2026-07-13 3 mo ago also EUVD-2026-43120
- cvss
- 6.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 39%
- public exploits
- 0
- none known
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 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.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
Affected products
- gallerycreator SimpLy Gallery
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/29b1984d-e6da-49d5-8b40-cdf2f1bcc1bb?source=cve
- plugins.trac.wordpress.org /browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L95
- plugins.trac.wordpress.org /browser/simply-gallery-block/trunk/blocks/init.php#L95
- plugins.trac.wordpress.org /browser/simply-gallery-block/trunk/blocks/init.php#L122
- plugins.trac.wordpress.org /browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L122
- plugins.trac.wordpress.org /browser/simply-gallery-block/trunk/blocks/init.php#L142
- plugins.trac.wordpress.org /browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L142
- plugins.trac.wordpress.org /browser/simply-gallery-block/trunk/blocks/init.php#L151
- plugins.trac.wordpress.org /browser/simply-gallery-block/tags/3.3.2.2/blocks/init.php#L151
- plugins.trac.wordpress.org /changeset?reponame=&old=3581386%40simply-gallery-block&new=3581386%40simply-gallery-block
Sources
- CVE List CVE-2026-5743
- NVD CVE-2026-5743
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.