ICS Calendar <= 12.0.9 - Reflected Cross-Site Scripting via 'htmltagtitle' Parameter
| CVE | CVE-2026-9838 |
|---|---|
| CVSS | 6.1 (Medium) |
| Publicly Published | July 9, 2026 |
| Last Updated | July 10, 2026 |
| Researcher |
Khanh Nguyen
- BlueRock
|
Description
The ICS Calendar plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'htmltagtitle' parameter in all versions up to, and including, 12.0.9 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 vulnerability is reachable via the unauthenticated wp_ajax_nopriv_r34ics_ajax AJAX action, which accepts attacker-controlled js_args values merged over stored shortcode configuration without nonce verification, allowing the htmltagtitle key to bypass the normal shortcode allowlist check.
Learn more about Cross-Site Scripting vulnerabilities and how to prevent them.
References
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
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Vulnerability Details for ICS Calendar
| Software Type | Plugin |
|---|---|
| Software Slug | ics-calendar (view on wordpress.org) |
| Patched? | Yes |
| Remediation | Update to version 12.0.9.2, or a newer patched version |
| Affected Version |
|
| Patched Version |
|
Recent vulnerabilities in ICS Calendar
| # | Title | CVE ID | CVSS | Researchers | Date |
|---|---|---|---|---|---|
| 1 | ICS Calendar <= 12.1.1 - Unauthenticated Stored Cross-Site Scripting | CVE-2026-59516 | Nguyen Ba Khanh | July 10, 2026 | |
| 2 | ICS Calendar <= 10.12.0.2 - Authenticated (Contributor+) Arbitrary File Read and Server-Side Request Forgery | CVE-2023-46784 | Muhammad Daffa | October 26, 2023 | |
| 3 | ICS Calendar <= 10.12.0.1 - Authenticated(Contributor+) Directory Traversal via _url_get_contents | CVE-2023-46784 | Muhammad Daffa | October 23, 2023 |
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