ICS Calendar <= 12.0.9 - Reflected Cross-Site Scripting via 'htmltagtitle' Parameter
Summary
| CVE | CVE-2026-9838 |
|---|---|
| State | PUBLISHED |
| Assigner | Wordfence |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-10 09:16:54 UTC |
| Updated | 2026-07-10 15:43:30 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 6.1 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS: 0.002960000 probability, percentile 0.214410000 (date 2026-07-13)
Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 6.1 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| 3.1 | CNA | DECLARED | 6.1 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
ChangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Room34 | ICS Calendar | affected 12.0.9 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.5.2/r34ics-ajax.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/changeset | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.8.4/r34ics-ajax.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.8.4/r34ics-ajax.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.5.2/templates/calendar-month.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.5.2/r34ics-ajax.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.5.2/r34ics-ajax.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.8.4/templates/calendar-month.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.8.4/r34ics-ajax.php | [email protected] | plugins.trac.wordpress.org | |
| www.wordfence.com/threat-intel/vulnerabilities/id/a4d91b01-5034-42b5-857f-c66c8... | [email protected] | www.wordfence.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Khanh Nguyen (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-07-09T19:52:56.000Z | Disclosed |
There are currently no legacy QID mappings associated with this CVE.