CVE-2026-48939: iCagenda Unrestricted Upload of File with Dangerous Type Vulnerability

This vulnerability affects the iCagenda component and stems from an unrestricted file upload weakness in its attachment feature. Attackers can submit files of dangerous types that the application does not properly validate, resulting in the placement and execution of PHP code on the server.

How it works

The flaw is categorized as CWE-434, unrestricted upload of file with dangerous type. In this class of weakness the application accepts user-supplied files without sufficiently restricting their content type, extension, or destination. An attacker supplies a file through the attachment mechanism; because no effective server-side controls block executable content, the file is stored in a web-accessible location and can later be requested to run server-side code.

Am I affected? How to find it in your systems

• Inventory all instances of iCagenda running in your web environments, including development, staging, and production servers.
• Review the configuration of the file attachment feature to determine whether upload restrictions are enabled and enforced.
• Compare installed versions and settings against the vendor advisory, as specific affected releases are not listed in the summary.
• Examine web-server logs and file-system monitoring for unexpected uploads to attachment directories or the appearance of files with executable extensions in web roots.
• Check application and PHP error logs for execution attempts originating from attachment paths.

How to remediate

Apply the vendor-supplied update referenced in the official advisory as the primary remediation. After patching, review and tighten file-upload controls for the attachment feature: enforce an allow-list of permitted MIME types and extensions, store uploaded files outside the web root, and rename files on receipt so that executable extensions are never preserved.

• Disable or remove the attachment feature if it is not required.
• Implement server-level rules that prevent execution of scripts in upload directories.
• Confirm that the changes match the guidance provided by the vendor.

If you can't patch immediately

• Place the affected application behind a web application firewall configured to inspect and block requests containing executable file uploads.
• Segment the server so that it cannot reach other internal systems if compromise occurs.
• Disable the file attachment capability until the update can be applied.
• Increase monitoring of web logs and file integrity for the attachment directories and web root.
• Follow CISA BOD 26-04 guidance for prioritizing and applying security updates, including evaluation of internet exposure.

If your data may have been exposed

Active exploitation of upload vulnerabilities has led to unauthorized access and data exposure in other environments. Organizations can run a free exposure scan of their email addresses against known breach data to determine whether related credentials or information have already appeared in public records.