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)

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.014 (72.2th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 72nd percentile — 72.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-78159: held from 0.014 to 0.014.

EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

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.
Is CVE-2026-78159 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.