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Vulnerability record · CVE-2026-78006 · published 12 September 2026

CVE-2026-78006: Deserialization of untrusted data vulnerability

The The Events Calendar plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 6.17.4 via the is_safe_widget_instance function. This is due to insufficient protection in is_safe_widget_instance, which can be bypassed because PHP fires magic methods during its pre-parse, combined with enable_rendering_widget_copied() forging a valid wp_hash integrity attribute before unserialize() is reached. This makes it possible for unauthenticated attackers to execute code on the server. This is exploitable without authentication or approval because the plugin's V2 single-event template runs do_blocks() over buffered comment HTML, and WordPress returns a moderation-hash URL that allows an unauthenticated commenter to immediately view their own pending comment, delivering the injected block markup to the vulnerable code path before any moderation occurs. This does require comments to be enabled and visible on events.

9.8 CVSS 3.1 Critical EPSS 1.5% · top 27.3% CWE-502 · Deserialization of untrusted data Deferred
9.8CVSS 3.1 base score
1.5%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
7References
14 Sep 2026Last modified by NVD

Description

The The Events Calendar plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 6.17.4 via the is_safe_widget_instance function. This is due to insufficient protection in is_safe_widget_instance, which can be bypassed because PHP fires magic methods during its pre-parse, combined with enable_rendering_widget_copied() forging a valid wp_hash integrity attribute before unserialize() is reached. This makes it possible for unauthenticated attackers to execute code on the server. This is exploitable without authentication or approval because the plugin's V2 single-event template runs do_blocks() over buffered comment HTML, and WordPress returns a moderation-hash URL that allows an unauthenticated commenter to immediately view their own pending comment, delivering the injected block markup to the vulnerable code path before any moderation occurs. This does require comments to be enabled and visible on events.

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

References

LinkTags
https://plugins.trac.wordpress.org/browser/the-events-calendar/tags/6.17.3/common/src/Tribe/Utils/Collection_Trait.php#L
https://plugins.trac.wordpress.org/browser/the-events-calendar/tags/6.17.3/src/Tribe/Collections/Lazy_Post_Collection.ph
https://plugins.trac.wordpress.org/browser/the-events-calendar/tags/6.17.3/src/Tribe/Views/V2/Template_Bootstrap.php#L21
https://plugins.trac.wordpress.org/browser/the-events-calendar/tags/6.17.3/src/Tribe/Views/V2/Widgets/Service_Provider.p
https://plugins.trac.wordpress.org/browser/the-events-calendar/tags/6.17.3/src/Tribe/Views/V2/Widgets/Service_Provider.p
https://plugins.trac.wordpress.org/changeset?reponame=&old=3690576%40the-events-calendar&new=3690576%40the-events-calend
https://www.wordfence.com/threat-intel/vulnerabilities/id/a0c67346-534a-4b67-a904-fa148703707a?source=cve

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Source: NIST National Vulnerability Database (record CVE-2026-78006), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.