InvoicePlane - Path Traversal (CVE-2026-23491)

CVE-2026-23491 is a critical path traversal vulnerability in InvoicePlane through version 1.6.3 that allows unauthenticated attackers to read arbitrary files on the server by manipulating the filename input. Exploitation can expose sensitive data, including configuration files and database credentials, potentially enabling further compromise of connected systems. InvoicePlane 1.6.4 addresses the issue.

CrowdSec has been tracking this vulnerability and its exploits since 17th of September 2026.

According to CrowdSec data, while opportunistic exploitation dominates, a portion of threat actors trying to exploit CVE-2026-23491 apply basic targeting methods such as port or service detection. This indicates emerging patterns of selective targeting. CrowdSec data also reveals a clear uptick in attacks involving CVE-2026-23491 over the past week. Activity is above the usual baseline, suggesting growing attention from attackers. This may reflect rising awareness, recent exploit releases, or expanded targeting efforts.

Attackers target the InvoicePlane guest file-download endpoint at /index.php/guest/get/get_file/, supplying encoded ../ traversal sequences to access files outside the intended upload directory, such as ipconfig.php. Successful exploitation may disclose application configuration, database credentials, and encryption keys in an attachment response.