RCE in Stellarwp The Events Calendar

CVE-2026-78159

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.

Vulnerability class: RCE (Remote Code Execution)

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-78159?
CVE-2026-78159 is a critical-severity vulnerability in Stellarwp The Events Calendar, classified under Code Injection. CVSS score: 9.8/10. Published 2026-09-12.
How severe is CVE-2026-78159?
Critical severity. CVSS v3 base score is 9.8 out of 10.