Skip to content
OpenAdvisories
Critical · 9.8 Public exploit CVE-2026-78006 EUVD-2026-76832GHSA-4q25-cq4p-f83q

The Events Calendar <= 6.17.4 - Unauthenticated PHP Object Injection to Remote Code Execution

Published Sep 12, 2026 · Updated Sep 14, 2026 · Assigned by Wordfence

Vendor: stellarwp Product: The Events Calendar Category: Web / CMS

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.

Affected products

VendorProductAffectedFixed
stellarwp The Events Calendar ≤ 6.17.4 —

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 2 repositories

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

References