Reflected XSS via AJAX shortcode override
Published Jul 10, 2026 · Updated Jul 10, 2026
Reflected XSS in Room 34 Creative Services, LLC's ICS Calendar 12.0.9 and earlier allows remote attackers to execute scripts via htmltagtitle. The unauthenticated wp_ajax_nopriv_r34ics_ajax action merges attacker-controlled js_args over stored shortcode configuration without a nonce, letting htmltagtitle bypass the shortcode allowlist and reach output without sufficient escaping. A victim must follow a crafted link; the injected script runs in that victim's WordPress origin and can read or modify browser-accessible site data.
Summary
What happened
Reflected XSS in Room 34 Creative Services, LLC's ICS Calendar 12.0.9 and earlier allows remote attackers to execute scripts via htmltagtitle. The unauthenticated wp_ajax_nopriv_r34ics_ajax action merges attacker-controlled js_args over stored shortcode configuration without a nonce, letting htmltagtitle bypass the shortcode allowlist and reach output without sufficient escaping. A victim must follow a crafted link; the injected script runs in that victim's WordPress origin and can read or modify browser-accessible site data.
The record
- CVE
- CVE-2026-9838
- Published
- Jul 10, 2026
- Updated
- Jul 10, 2026
- Vendor
- Room 34 Creative Services, LLC
- Product
- ICS Calendar
- Classifications
- CWE-79, T1204.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 10, 2026CVE publishedPublication date reported by the CVE source.
- Jul 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=12.0.9
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo