CVE-2026-109989 themifyme CVE debrief

Who should care

WordPress administrators and users with author-level access and above who use the Themify Popup plugin should assess their exposure and take defensive actions. This includes verifying the version of the Themify Popup plugin, implementing input sanitization and output escaping for the 'popup_width_unit' parameter, and monitoring for potential exploitation attempts.

Why it matters

The Themify Popup plugin for WordPress has a Stored Cross-Site Scripting vulnerability that allows authenticated attackers to inject arbitrary web scripts, which can execute on pages accessed by users. WordPress administrators and users with author-level access and above should assess their exposure and take defensive actions.

• Authenticated attackers with author-level access and above can inject arbitrary web scripts
• Injected scripts can execute on pages accessed by users
• Defenders should verify the version of the Themify Popup plugin and update to a fixed version
• Defenders should implement input sanitization and output escaping for the 'popup_width_unit' parameter

Technical summary

The Themify Popup plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'popup_width_unit' parameter in all versions up to, and including, 1.4.7 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Defensive priority

Medium-priority defensive actions are recommended to address this vulnerability.

Recommended defensive actions

• Update the Themify Popup plugin to a version that fixes the vulnerability
• Implement input sanitization and output escaping for the 'popup_width_unit' parameter
• Monitor for potential exploitation attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description and CVSS score. The Themify Popup plugin for WordPress has a Stored Cross-Site Scripting vulnerability that allows authenticated attackers to inject arbitrary web scripts, which can execute on pages accessed by users. The vulnerability is caused by insufficient input sanitization and output escaping for the 'popup_width_unit' parameter in all versions up to, and including, 1.4.7. Defenders should verify the version of the Themify Popup plugin,

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.