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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00296.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
room34 ICS Calendar unaffected
Version Status Constraints
0 affected ≤ 12.0.9

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Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.5.2/r34ics-ajax.php#L33 cve-icon
https://plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.5.2/r34ics-ajax.php#L53 cve-icon
https://plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.5.2/r34ics-ajax.php#L72 cve-icon
https://plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.5.2/templates/calendar-month.php#L40 cve-icon
https://plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.8.4/r34ics-ajax.php#L33 cve-icon
https://plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.8.4/r34ics-ajax.php#L53 cve-icon
https://plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.8.4/r34ics-ajax.php#L72 cve-icon
https://plugins.trac.wordpress.org/browser/ics-calendar/tags/12.0.8.4/templates/calendar-month.php#L40 cve-icon
https://plugins.trac.wordpress.org/changeset?reponame=&old=3563728%40ics-calendar&new=3563728%40ics-calendar cve-icon
https://www.wordfence.com/threat-intel/vulnerabilities/id/a4d91b01-5034-42b5-857f-c66c875dd562?source=cve cve-icon
History

Fri, 10 Jul 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Fri, 10 Jul 2026 09:00:00 +0000

Type Values Removed Values Added
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.
Title ICS Calendar <= 12.0.9 - Reflected Cross-Site Scripting via 'htmltagtitle' Parameter
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Wordfence

Published:

Updated: 2026-07-10T14:04:31.963Z

Reserved: 2026-05-28T12:59:23.830Z

Link: CVE-2026-9838

cve-icon Vulnrichment

Updated: 2026-07-10T14:04:28.701Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses