Stored XSS Vulnerability in SOPlanning by Open-Source Developer
CVE-2026-40544

5.1MEDIUM

Key Information:

Vendor

Soplanning

Status
Soplanning
Vendor
CVE Published:
1 June 2026

What is CVE-2026-40544?

SOPlanning is susceptible to a Stored Cross-Site Scripting (XSS) vulnerability through the /process/upload_backup endpoint. An authenticated user with backup functionality access can upload a specially crafted ZIP file containing a malicious user.csv file. This file, when executed, injects JavaScript code that runs in the browser of any victim who interacts with the malicious backup by clicking the Edit button. This risk primarily impacts SOPlanning version 1.55 and any earlier versions.

Affected Version(s)

SOPlanning 0 <= 1.55

References

https://cert.pl/en/posts/2026/06/CVE-2026-40543
third-party-advisory
https://www.soplanning.org/en/
product

CVSS V4

Score:
5.1
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Łukasz Jaworski
.