Attack Chain

1. An attacker obtains valid authentication credentials for the Bold Reports Standalone Report Designer application.
2. The authenticated attacker accesses the application's file upload functionality.
3. The attacker crafts a malicious filename containing path traversal sequences (e.g., ../../../../webshell.jsp) and attempts to upload it.
4. Due to the missing filepath validation (CVE-2026-65690), the application fails to properly sanitize the filename.
5. The malicious file (e.g., a web shell or script) is written to an arbitrary location on the server, outside the intended upload directory.
6. The attacker then accesses the uploaded malicious file (e.g., the web shell) through a web request.
7. The web shell executes arbitrary commands with the privileges of the application, potentially leading to high-privileged system access or further compromise.

Impact

Successful exploitation of CVE-2026-65690 grants authenticated attackers the ability to execute arbitrary commands with high privileges on the compromised server. This can lead to a complete system takeover, allowing for sensitive data exfiltration, modification, or deletion, installation of additional malware such as ransomware or backdoors, and lateral movement within the network. The integrity and confidentiality of data stored on or accessible from the server are at severe risk. The broad impact of arbitrary command execution underscores the criticality of patching this vulnerability immediately.

Recommendation

• Patch Bold Reports Standalone Report Designer to version 14.1.12 or higher immediately to address CVE-2026-65690.
• Deploy the provided Sigma rule to your SIEM to detect attempts at path traversal through web server logs.
• Monitor web server logs for suspicious file upload activity and unusual file paths, particularly those referenced in the Sigma rule.