CVE-2025-22261
📋 TL;DR
This stored cross-site scripting (XSS) vulnerability in the WP FullCalendar WordPress plugin allows attackers to inject malicious scripts into web pages. When users view pages containing the injected scripts, the attacker can steal session cookies, redirect users, or perform actions on their behalf. All WordPress sites using WP FullCalendar versions up to 1.5 are affected.
💻 Affected Systems
- WP FullCalendar WordPress Plugin
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, take over WordPress sites, install backdoors, deface websites, or redirect visitors to malicious sites.
Likely Case
Attackers inject malicious JavaScript that steals user session cookies or redirects users to phishing pages when they view calendar pages.
If Mitigated
With proper input validation and output escaping, malicious scripts would be neutralized before reaching users.
🎯 Exploit Status
XSS vulnerabilities are commonly exploited, though specific exploit details for this CVE aren't publicly documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version after 1.5
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find WP FullCalendar and check if update is available. 4. Click 'Update Now' if update exists. 5. If no update appears, deactivate and remove the plugin immediately.
🔧 Temporary Workarounds
Disable WP FullCalendar Plugin
allTemporarily disable the vulnerable plugin until patched version is available
wp plugin deactivate wp-fullcalendar
Implement WAF Rules
allAdd web application firewall rules to block XSS payloads targeting calendar endpoints
🧯 If You Can't Patch
- Remove WP FullCalendar plugin completely and use alternative calendar solutions
- Implement Content Security Policy (CSP) headers to restrict script execution sources
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → Installed Plugins for WP FullCalendar version ≤1.5Check Version:
wp plugin get wp-fullcalendar --field=versionVerify Fix Applied:
Verify WP FullCalendar version is greater than 1.5 in WordPress plugins list📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to calendar endpoints with script tags
- Multiple failed XSS attempts in web server logs
Network Indicators:
- HTTP requests containing <script> tags to /wp-content/plugins/wp-fullcalendar/ endpoints
SIEM Query:
source="web_server" AND (uri="*wp-fullcalendar*" AND (body="*<script>*" OR body="*javascript:*"))