CVE-2026-40544

Description

SOPlanning is vulnerable to Stored Cross-Site Scripting (XSS) via /process/upload_backup endpoint. An authenticated attacker with access to the backup functionality can upload a crafted ZIP archive containing a malicious user.csv file with embedded JavaScript. The injected code is executed in the victim’s browser when a user clicks the Edit button for the malicious backup. This issue affects SOPlanning version 1.55 and below.

References

• https://cert.pl/en/posts/2026/06/CVE-2026-40543
• https://www.soplanning.org/en/