ICS Calendar <= 12.0.9 — Reflected Cross-Site Scripting via 'htmltagtitle' Parameter
CVE-2026-9838Published · Updated Action summary
Affected: ≤12.0.9Update to 12.0.9.2 or newer
All remediation steps- Severity
- Medium6.1
- CVSS
- 6.1CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:NPrivileges required- None
UI:RUser interaction- Required
S:CScope- Changed
C:LConfidentiality- Low
I:LIntegrity- Low
A:NAvailability- None
- Weakness
- CWE-79 Cross-Site Scripting
- Required access
- No account needed
- Exploit prediction (EPSS)
- No score
- CISA KEV
- Not listed
On this page8
Am I affected?
ICS Calendar ics-calendar
- Affected≤ 12.0.9
- Patched in12.0.9.2
Update to 12.0.9.2 or newer.
You are affected if you run ≤ 12.0.9. Version 12.0.9.2 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under ICS Calendar.
- No admin access? Run a passive check of your site. It reads public files only.
- No account is needed to exploit this. Treat any exposed site on an affected version as at risk.
What to do
- Update to version 12.0.9.2, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch ICS Calendar to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to Khanh Nguyen.
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.
Exploits & references
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Related CVEs
More in ICS Calendar
All 4| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| High7.2 | Unauthenticated Stored Cross-Site Scripting ≤12.1.1Update to 12.1.1.1 | CVE-2026-59516 | |
| High8.8 | Authenticated (Contributor+) Arbitrary File Read and Server-Side Request Forgery ≤10.12.0.2Update to 10.12.0.3 | CVE-2023-46784 | |
| Medium6.5 | Authenticated(Contributor+) Directory Traversal via _url_get_contents <10.12.0.2Update to 10.12.0.2 | — |
- High7.2Unauthenticated Stored Cross-Site Scripting
≤12.1.1Update to 12.1.1.1
- High8.8Authenticated (Contributor+) Arbitrary File Read and Server-Side Request Forgery
≤10.12.0.2Update to 10.12.0.3
- Medium6.5Authenticated(Contributor+) Directory Traversal via _url_get_contents
<10.12.0.2Update to 10.12.0.2
Same weakness (Cross-Site Scripting)
All Cross-Site Scripting| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| High7.2 | Unauthenticated Stored Cross-Site Scripting via Comment User-Agent Header | CVE-2026-120688 | |
| Critical9.8 | Unauthenticated Arbitrary File Upload via File Upload via Public Form Submission | CVE-2026-125055 | |
| Critical9.8 | Unauthenticated PHP Object Injection to Remote Code Execution via 'form' Parameter | CVE-2026-119077 | |
| Medium5.3 | Unauthenticated Sensitive Information Exposure in 'search' Parameter | CVE-2026-121518 |
- High7.2Unauthenticated Stored Cross-Site Scripting via Comment User-Agent Header
EZ SQL Reports Shortcode Widget and DB Backup
≤5.25.25Update to 5.26.45
- Critical9.8Unauthenticated Arbitrary File Upload via File Upload via Public Form Submission
Chatterbug Forms – Fast, Flexible WordPress Form Builder
≤1.0.2Update to 1.1
- Critical9.8Unauthenticated PHP Object Injection to Remote Code Execution via 'form' Parameter
ELEX WordPress HelpDesk & Customer Ticketing System
≤3.3.9Update to 3.4.0
- Medium5.3Unauthenticated Sensitive Information Exposure in 'search' Parameter
Customer Reviews for WooCommerce
≤5.127.0Update to 5.128.0
Timeline
CVE published
Severity medium, CVSS 6.1
Record last updated
Sources & licenses
Wordfence record- Vulnerability data
- Wordfence Intelligence. [object Object] Licensed under the CC BY-SA 4.0.
- CVE® identifiers
- [object Object]. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
- CVSS / CWE
- National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
- VulnCrest content
- Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.