CVE-2025-49298 Overview
CVE-2025-49298 is a stored Cross-Site Scripting (XSS) vulnerability in the Bastien Ho Event post WordPress plugin. The flaw affects all versions up to and including 5.10.1 and stems from improper neutralization of user-supplied input during web page generation [CWE-79]. An authenticated attacker with low privileges can inject malicious JavaScript that persists in the plugin's output. The payload executes in the browser of any user who views the affected page, enabling session theft, forced redirection, or administrative action abuse through the victim's authenticated session.
Critical Impact
Authenticated attackers can inject persistent JavaScript that executes in victim browsers, compromising session integrity and enabling cross-user attacks within the WordPress site.
Affected Products
- Bastien Ho Event post plugin for WordPress
- All versions from n/a through 5.10.1
- WordPress sites with the Event post plugin installed and active
Discovery Timeline
- 2025-06-06 - CVE-2025-49298 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-49298
Vulnerability Analysis
The vulnerability is a stored XSS flaw in the Event post plugin for WordPress. The plugin accepts input from authenticated users and renders it back into web pages without adequate sanitization or output encoding. Because the payload is stored server-side, every subsequent request that renders the affected view triggers the injected script.
Stored XSS in a WordPress plugin provides a durable foothold. Script execution occurs in the context of the hosting site, allowing attackers to read cookies, manipulate the Document Object Model (DOM), issue authenticated requests on behalf of victims, or stage further payloads. The scope change in the CVSS vector reflects impact beyond the vulnerable component, since injected scripts can affect administrators and other users who merely view the content.
Root Cause
The root cause is improper neutralization of input during web page generation [CWE-79]. The plugin fails to apply WordPress sanitization helpers such as wp_kses_post() or esc_html() on user-controlled fields before storing or rendering them. As a result, HTML and JavaScript supplied by a contributor-level or higher account survive the write path and execute at render time.
Attack Vector
Exploitation requires network access, low privileges on the WordPress site, and user interaction to view the injected content. An attacker authenticates with an account permitted to create or edit event content, then submits a crafted payload containing HTML attributes or <script> constructs targeting unsanitized fields. The stored payload executes when any user, including administrators, loads the page containing the malicious event data. See the Patchstack XSS Vulnerability Advisory for additional technical details.
Detection Methods for CVE-2025-49298
Indicators of Compromise
- Event post entries containing <script>, onerror=, onload=, or javascript: strings in title, description, or metadata fields
- Unexpected outbound HTTP requests originating from authenticated admin sessions after viewing event pages
- New or modified WordPress administrator accounts following contributor-level user activity
- Browser console errors or Content Security Policy (CSP) violations tied to event-post rendered pages
Detection Strategies
- Query the WordPress database for event-post content containing HTML event handlers or script tags
- Review web server access logs for POST requests to event-post endpoints from low-privilege user accounts
- Monitor for anomalous session activity correlated with page views of event-post content
- Deploy a Web Application Firewall (WAF) rule to flag XSS payload patterns submitted to plugin endpoints
Monitoring Recommendations
- Enable WordPress audit logging for post creation, modification, and user role changes
- Alert on administrator account creation or privilege elevation within short windows of event-post activity
- Track plugin version inventory across WordPress sites to identify instances still running 5.10.1 or earlier
How to Mitigate CVE-2025-49298
Immediate Actions Required
- Update the Event post plugin to a version later than 5.10.1 once a patched release is published
- Audit all existing event-post entries for stored HTML or script payloads and remove suspicious content
- Restrict contributor and author account creation and review existing low-privilege accounts for legitimacy
- Rotate administrator credentials and invalidate active sessions if indicators of exploitation are found
Patch Information
Consult the Patchstack XSS Vulnerability Advisory for current patch availability. At time of publication, the advisory lists all versions through 5.10.1 as affected. Administrators should subscribe to plugin update notifications and apply fixed releases immediately upon availability.
Workarounds
- Deactivate the Event post plugin until a patched version is available if event functionality is non-essential
- Deploy a WAF rule that blocks requests containing script tags or JavaScript event handlers targeting event-post endpoints
- Enforce a strict Content Security Policy (CSP) that disallows inline scripts to reduce exploit payload execution
- Limit account creation and restrict publishing privileges to trusted users only
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
