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CVE-2026-78159

The Events Calendar <= 6.17.3 - Unauthenticated Code Injection to Remote Code Execution via Widget 'classes' Map Callable Invocation

Published: Sep 12, 2026Updated: Sep 14, 2026 Sources: CVE List NVDCWE-94
9.8CRITICAL
NVD MITRE
EPSS Score
0.8%
Top 46.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

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.

In plain language

AI Act now

CVE-2026-78159 is a critical WordPress plugin flaw that can let an unauthenticated attacker run code on your server through event comments, but only if your site has comments enabled on event pages and a crafted widget-style comment is present—this is worth acting on if you run The Events Calendar.

Executive summary

Unauthenticated Remote Code Execution is possible in The Events Calendar (all versions up to and including 6.17.3) via a crafted `wp:legacy-widget` comment payload that reaches Element_Classes::parse_array(), bypassing safety checks for the widget `classes` map and invoking callable code.

If affected, business impact
Full server takeoverCustomer data exposureWebsite defacementService disruptionMalware/ransomware pivot

What to do now

  1. Check whether your WordPress site uses “The Events Calendar” and note its exact plugin version.
  2. Verify comments are enabled for tribe_events posts, and whether visitors can submit comments (including on single-event pages).
  3. Search your database or WordPress comment storage for suspicious wp:legacy-widget blocks inside comments on tribe_events posts.
  4. If you are on version 6.17.3 or earlier, update The Events Calendar to the fixed release your vendor provides (no fixed version was identified in the available patch findings).
  5. If you cannot patch immediately, restrict who can post comments on tribe_events pages (disable comments or require moderation) and remove any suspicious comments containing wp:legacy-widget blocks.
May need vendor / contractor work

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
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Weaknesses

CWE-94

Affected Products

stellarwp
commercial
The Events CalendarOn-premCMS Plugin
Web & CMS Plugins / wordpress-plugin

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
Is your org exposed to CVE-2026-78159?Request an assessment to establish which checks are appropriate for your systems. Check my exposure

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Execution
Initial Access
View detailed technique mapping

References

https://www.wordfence.com/threat-intel/vulnerabilities/id/cc2ccfeb-6df6-4fee-96a5-94f8dd131f7c?source=cve
wordfence.com
https://plugins.trac.wordpress.org/browser/the-events-calendar/tags/6.17.3/common/src/Tribe/Utils/Element_Classes.php#L211
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/the-events-calendar/tags/6.17.3/src/views/v2/components/messages.php#L30
plugins.trac.wordpress.org
and 4 more references View all →
News mentions
2

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