Critical severity · published Sep 12, 2026
CVE-2026-78159
The Events Calendar <= 6.17.3 - Unauthenticated Code Injection to Remote Code Execution via Widget 'classes' Map Callable Invocation
9.8
CVSS
1.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.4% · higher than 72% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TE
The Events Calendar · stellarwp
through 6.17.3 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-78159
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-78159
plugins.trac.wordpress.org
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/Tribe/Views/V2/Template_Bootstrap.php#L214
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/the-events-calendar/tags/6.17.3/src/Tribe/Views/V2/Widgets/Service_Provider.php#L279
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
https://plugins.trac.wordpress.org/changeset?reponame=&old=3667866%40the-events-calendar&new=3667866%40the-events-calendar
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/changeset?reponame=&old=3667867%40the-events-calendar&new=3667867%40the-events-calendar
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