---
id: CVE-2026-3367
title: >-
  The Lockme OAuth2 calendars integration plugin for WordPress is vulnerable to
  Stored Cross-Site Scripting via the 'App ID' setting in all versions up to,
  and including, 2.11.0
summary: >-
  The Lockme OAuth2 calendars integration plugin for WordPress is vulnerable to
  Stored Cross-Site Scripting via the 'App ID' setting in all versions up to,
  and including, 2.11.0. This is due to insufficient input sanitization and
  output es…
severity: medium
cvss: 4.4
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
published: '2026-07-11'
updated: '2026-07-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-3367'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L197
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L212
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L223
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L245
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L256
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L54
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L197
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L212
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L223
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L245
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L256
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L54
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset?reponame=&old=3495564%40lockme-calendars-integration&new=3495564%40lockme-calendars-integration
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/800b1a44-4173-4b8e-bc69-9a64218e64d6?source=cve
    label: security@wordfence.com
tags:
  - nvd
epss: 0.00412
epssPercentile: 0.35192
ingestedAt: '2026-07-11T22:16:01.218Z'
---

## Overview

The Lockme OAuth2 calendars integration plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'App ID' setting in all versions up to, and including, 2.11.0. This is due to insufficient input sanitization and output escaping. The register_setting() call on line 197 lacks a sanitize callback, allowing unsanitized data to be stored via update_option(). When the settings page is rendered, the stored value is echoed directly into an HTML input's value attribute without esc_attr() on line 212. This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary web scripts in the settings page that will execute whenever a user accesses the plugin settings page. Multiple fields are affected: App ID (client_id), App Secret (client_secret), Bookings ID prefix (id_prefix), and API domain (api_domain). This vulnerability is particularly impactful in WordPress multisite installations where administrators of individual sites should not be able to execute JavaScript affecting other users.

## Remediation

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