---
id: CVE-2026-17089
title: >-
  The Events Manager – Calendar, Bookings, Tickets, and more! plugin for
  WordPress is vulnerable to Reflected Cross-Site Scripting via the
  'header_format' parameter in all versions up to, and including, 7.4.0.1 due to
  insufficient input sa…
summary: >-
  The Events Manager – Calendar, Bookings, Tickets, and more! plugin for
  WordPress is vulnerable to Reflected Cross-Site Scripting via the
  'header_format' parameter in all versions up to, and including, 7.4.0.1 due to
  insufficient input sa…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
published: '2026-08-25'
updated: '2026-10-12'
sourceUpdated: '2026-10-12T15:10:00.207'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-17089'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/events-manager/tags/7.3.4/classes/em-events.php#L469
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/events-manager/tags/7.3.4/classes/em-object.php#L1176
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/events-manager/tags/7.3.4/em-actions.php#L891
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/events-manager/tags/7.3.4/em-actions.php#L920
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/events-manager/tags/7.4.0.1/classes/em-events.php#L469
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/events-manager/tags/7.4.0.1/classes/em-object.php#L1176
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/events-manager/tags/7.4.0.1/em-actions.php#L891
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/events-manager/tags/7.4.0.1/em-actions.php#L920
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset?old_path=/events-manager/tags/7.4.0.1&new_path=/events-manager/tags/7.4.1
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/a56d1a9e-7564-41b0-af03-c272ffbbbb97?source=cve
    label: security@wordfence.com
tags:
  - nvd
  - exploit-available
epss: 0.00408
epssPercentile: 0.33137
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/pwnVader/CVE-2026-17089-PoC-pwnVader'
  checkedAt: '2026-10-12T15:55:43.154Z'
exploitAvailable: true
ingestedAt: '2026-10-12T15:55:08.150Z'
---

## Overview

The Events Manager – Calendar, Bookings, Tickets, and more! plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'header_format' parameter in all versions up to, and including, 7.4.0.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. The shortcode entry point sanitizes 'header_format' via wp_kses(), but the unauthenticated 'search_events_grouped' AJAX action bypasses this sanitization entirely, leaving the parameter unsanitized before it is echoed into the HTML body in output_grouped().

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.