Unauthenticated shortcode execution via unvalidated view_data
Published Oct 2, 2026 · Updated Oct 2, 2026
Improper input validation in The Events Calendar 6.12.0 through 6.17.5 allows remote attackers to execute site-registered shortcodes via AJAX. The unauthenticated view_data parameter is merged into the view-rendering context without validation or sanitization, allowing submitted values to reach shortcode processing. Exploitation requires a useful shortcode registered on the site; the reported behavior does not establish arbitrary PHP-code execution.
Summary
What happened
Improper input validation in The Events Calendar 6.12.0 through 6.17.5 allows remote attackers to execute site-registered shortcodes via AJAX. The unauthenticated view_data parameter is merged into the view-rendering context without validation or sanitization, allowing submitted values to reach shortcode processing. Exploitation requires a useful shortcode registered on the site; the reported behavior does not establish arbitrary PHP-code execution.
The record
- CVE
- CVE-2026-84740
- Published
- Oct 2, 2026
- Updated
- Oct 2, 2026
- Vendor
- Nexcess
- Product
- The Events Calendar
- Classifications
- T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 2, 2026CVE publishedPublication date reported by the CVE source.
- Oct 2, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.12.0 <6.17.5.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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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.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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