XSS in Soplanning
CVE-2026-40544
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
EPSS exploit prediction
EPSS: 0.004 (32.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 32.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Soplanning — versions 0
Weakness classification (CWE)
References
- cert.pl/en/posts/2026/06/CVE-2026-40543 (third-party-advisory)
- www.soplanning.org/en/ (product)