PatchSiren cyber security CVE debrief
CVE-2026-5743 gallerycreator CVE debrief
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.
- Vendor
- gallerycreator
- Product
- SimpLy Gallery
- CVSS
- MEDIUM 6.4
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-11
- Original CVE updated
- 2026-07-11
- Advisory published
- 2026-07-11
- Advisory updated
- 2026-07-11
Who should care
Users of the SimpLy Gallery Block & Lightbox plugin for WordPress, particularly those with Author-level access and above, should be aware of this vulnerability and take steps to mitigate it. This vulnerability could allow attackers to inject malicious scripts into pages, potentially leading to security breaches.
Technical 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. The vulnerability is caused by insufficient input sanitization and output escaping on the sliderMaxHeight block attribute in the pgc_sgb_render_callback() function. The pgc_sgb_sanitize_custom_css() function uses a flawed regex pattern that fails to catch unquoted event handlers, allowing malicious code to bypass sanitization.
Defensive priority
Medium
Recommended defensive actions
- Update the SimpLy Gallery Block & Lightbox plugin to a version that fixes this vulnerability.
- Limit access to the plugin's settings and block attributes to trusted users only.
- Monitor pages for suspicious activity and injected scripts.
- Consider implementing a Web Application Firewall (WAF) to detect and prevent common web attacks.
- Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
- Review compensating controls for exposed systems while remediation is scheduled and verified.
- Track exceptions, retest remediated assets, and close the item only after evidence is documented.
Evidence notes
The CVE record was published on 2026-07-11T04:17:23.843Z and has not been modified since then. The NVD entry is currently 6.4, MEDIUM. The vulnerability was reported by [email protected]. Evidence is limited to public sources and may not reflect the full scope of affected deployments. Defenders should verify potential exposure and review vendor guidance for mitigation steps.
Official resources
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-11T04:17:23.843Z and has not been modified since then.