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PatchSiren cyber security CVE debrief

CVE-2026-87915 danieliser CVE debrief

The Popup Maker plugin for WordPress, versions up to and including 1.24.0, is vulnerable to Stored Cross-Site Scripting via the values[Name] parameter. This allows unauthenticated attackers to inject arbitrary web scripts that execute when a user accesses an injected page. The vulnerability stems from insufficient input sanitization and output escaping. The wp_kses sanitization applied on output is insufficient 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. Defenders should prioritize verifying and updating thePopup

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

Defenders responsible for WordPress sites using the Popup Maker plugin should assess exposure and prioritize updating the plugin to prevent exploitation. This includes reviewing the plugin versions in use, verifying the presence of the vulnerability, and applying the necessary patches. Additionally, defenders should monitor for suspicious activity and implement compensating controls where necessary.

Why it matters

The Popup Maker plugin for WordPress is vulnerable to Stored Cross-Site Scripting, allowing unauthenticated attackers to inject arbitrary web scripts. Defenders should prioritize verifying and updating the plugin to prevent exploitation.

  • Unauthenticated attackers can inject arbitrary web scripts
  • Injected scripts execute when a user accesses an injected page
  • Insufficient sanitization and output escaping enable the vulnerability

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, and including, 1.24.0. This allows unauthenticated attackers to inject arbitrary web scripts that execute when a user accesses an injected page. 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 prevent exploitation.

Recommended defensive actions

  • Verify and update the Popup Maker plugin to the latest version
  • Monitor for suspicious activity on WordPress sites using the Popup Maker plugin
  • Implement additional security measures to prevent cross-site scripting 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 CVE record and NVD entry provide details on the vulnerability, including its description and CVSS score. The vulnerability was publicly disclosed on 2026-09-18T10:17:07.717Z. The wp_kses sanitization applied on output is insufficient in this context because HTML entities within allowed attribute values survive normalization intact. The jQuery(link.attr('href')) sink in wp-admin/js/common.js evaluates these entities when a contextual help tab anchor is clicked. There are references to Database.php, Table.php, and ListTable.php in

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.