Vulnerability · Published Jun 1, 2026 · Assigned by CERT-PL

CVE-2026-40544Stored XSS in SOPlanning

Medium 5.1

In plain English

A medium-severity cross-site scripting in SOPlanning from SOPlanning. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities).

Severity (CVSS 4.0)5.1Medium

Exploit odds (30 days)0.3%top 77.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
SOPlanning	SOPlanning	0 – through 1.55

Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N

References

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