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PatchSiren cyber security CVE debrief

CVE-2026-87915 danieliser CVE debrief

The Popup Maker plugin for WordPress has a Stored Cross-Site Scripting vulnerability via the values[Name] parameter in all versions up to 1.24.0. This allows unauthenticated attackers to inject web scripts that execute when a user accesses an injected page. The vulnerability is caused by insufficient input sanitization and output escaping. The wp_kses sanitization applied on output is insufficient in this context because HTML entities within allowed attribute values survive normalization intact and are later evaluated by the jQuery(link.attr('href')) sink in wp-admin/js/common.js when a contextual help tab anchor is clicked.

Vendor
danieliser
Product
Popup Maker – Boost Sales, Conversions, Optins, Subscribers with the Ultimate WP Popup Builder
CVSS
HIGH 7.2
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-18
Original CVE updated
2026-09-18
Advisory published
2026-09-18
Advisory updated
2026-09-18

Who should care

WordPress site administrators and defenders should assess exposure and prioritize updating the Popup Maker plugin to mitigate potential XSS attacks. Defenders should verify and update the plugin to prevent potential XSS attacks. Site administrators should monitor for potential XSS attacks on WordPress sites using the Popup Maker plugin.

Why it matters

The Popup Maker plugin for WordPress has a Stored Cross-Site Scripting vulnerability, allowing unauthenticated attackers to inject web scripts. Defenders should prioritize verifying and updating the plugin to mitigate potential XSS attacks.

  • Defenders should verify and update the Popup Maker plugin to prevent potential XSS attacks.
  • Site administrators should monitor for potential XSS attacks on WordPress sites using the Popup Maker plugin.
  • Implementing additional security measures can help prevent XSS attacks.

Technical summary

The Popup Maker plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the values[Name] parameter in all versions up to 1.24.0. This allows unauthenticated attackers to inject web scripts that execute when a user accesses an injected page. The vulnerability is caused by insufficient input sanitization and output escaping. The wp_kses sanitization applied on output is insufficient in this context because HTML entities within allowed attribute values survive normalization intact and are later evaluated by the jQuery(link.attr('href')) sink in wp-admin/js/common.js when a contextual help tab anchor is clicked.

Defensive priority

Defenders should prioritize verifying and updating the Popup Maker plugin to mitigate potential XSS attacks.

Recommended defensive actions

  • Verify and update the Popup Maker plugin to the latest version.
  • Monitor for potential XSS attacks on WordPress sites using the Popup Maker plugin.
  • Implement additional security measures to prevent XSS attacks.
  • 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 vulnerability is caused by insufficient input sanitization and output escaping in the Popup Maker plugin. The wp_kses sanitization applied on output is insufficient in this context. The CVE record was published on 2026-09-18T10:17:07.717Z and has not been modified since then. The source details are limited, and defenders should verify the vulnerability and update the plugin to mitigate potential XSS attacks.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-87915 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-87915

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-87915 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-87915

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental 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.