CVE-2026-87869 stepasyuk CVE debrief

Who should care

Defenders responsible for WordPress installations with the Filter Everything — WordPress & WooCommerce Filters plugin should assess exposure and prioritize patching or mitigation measures.

Why it matters

The Filter Everything — WordPress & WooCommerce Filters plugin for WordPress is vulnerable to Reflected Cross-Site Scripting in versions up to, and including, 1.9.6. This is due to insufficient input sanitization and output escaping in the flrt_elementor_load_more_anchor() function.

• Defenders must verify the version of the Filter Everything — WordPress & WooCommerce Filters plugin and apply patches or updates as needed to prevent potential exploitation.
• Implementing additional input sanitization and output escaping measures can help prevent similar vulnerabilities.
• Defenders should monitor for potential exploitation attempts and implement security measures to prevent attacks.

Technical summary

The Filter Everything — WordPress & WooCommerce Filters plugin for WordPress is vulnerable to Reflected Cross-Site Scripting in versions up to, and including, 1.9.6. This is due to insufficient input sanitization and output escaping in the flrt_elementor_load_more_anchor() function. The function reads query parameters from $_SERVER['REQUEST_URI'] via getFormActionOrFullPageUrl(true), which URL-decodes them through parse_str() and re-assembles them using build_query() — a WordPress core function that does NOT re-encode values ($urlencode=false). The resulting URL, containing unescaped special characters, is injected into a data-next-page HTML attribute via preg_replace() without esc_attr() or esc_url().

Defensive priority

Defenders should prioritize verifying the version of the Filter Everything — WordPress & WooCommerce Filters plugin and applying patches or updates as needed.

Recommended defensive actions

• Verify the version of the Filter Everything — WordPress & WooCommerce Filters plugin and apply patches or updates as needed.
• Implement additional input sanitization and output escaping measures to prevent similar vulnerabilities.
• Monitor for potential exploitation attempts and implement security measures to prevent 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 source item provide details on the vulnerability, including the affected version and the insufficient input sanitization and output escaping in the flrt_elementor_load_more_anchor() function.

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.