The Events Calendar comment blocks reach a callable execution sink

The Events Calendar through 6.17.3 can execute code without authentication when comments are enabled on tribe_events posts. A crafted wp:legacy-widget block in a comment supplies a plain-array widget classes map that bypasses is_safe_widget_instance() and reaches the callable sink in Element_Classes::parse_array() when do_blocks() processes the single-event comment area.

CVE / CNA score 9.8 CVSS 3.1 · security@wordfence.com

NVD score Pending NVD has not published its own CVSS assessment.

Component: The Events Calendar
Plugin slug: the-events-calendar
Affected: <= 6.17.3
Safe version: See mitigation notes
Published: Sep 12, 2026
Weakness: CWE-94 — Improper Control of Generation of Code ('Code Injection')

This CVE was published Sep 12, 2026 and is one of 28 known issues for this plugin.

What to do

Update, patch or deactivate.

No fixed release is confirmed in the authoritative export. Disable comments on event posts or deactivate the plugin until the vendor supplies a confirmed remediation. The application-level fix must reject attacker-controlled callable maps and prevent comment block markup from reaching widget callable invocation.

No confirmed safe version is listed. Consider a vendor-supported patch or temporarily restricting the affected functionality while you assess the risk.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Source record

Technical description

The The Events Calendar plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 6.17.3 via the parse_array function. This is due to insufficient validation of the widget 'classes' map, allowing a plain-array payload to bypass the is_safe_widget_instance() object check and reach the callable-invocation sink in Element_Classes::parse_array(). This makes it possible for unauthenticated attackers to execute code on the server. Exploitation requires that the targeted site has comments enabled on tribe_events posts and that at least one comment containing a crafted wp:legacy-widget block has been submitted, as the attack chain is triggered when do_blocks() processes the single-event HTML including the comment area.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Primary and upstream sources

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