Cross-site scripting vulnerability in LuxCal Web Calendar prior to 5.2.3M (MySQL version) and LuxCal Web Calendar prior to 5.2.3L (SQLite version) allows a remote unauthenticated attacker to execute an arbitrary script on the web browser of the user who is using the product.
Conclusion & alert: CVE-2023-39543 is rated Low Risk (38.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.53%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.27% | 0.53% | +0.26% |
| 2 | 2025-11-21 | 0.97% | 0.27% | -0.70% |
| 3 | 2025-11-18 | — | 0.97% | — |
Full EPSS history (12 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.1 | 3.1 | MEDIUM |
|
2.8 | 2.7 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| luxsoft | luxcal_web_calendar | < 5.2.3m | cpe:2.3:a:luxsoft:luxcal_web_calendar:*:*:*:*:*:*:*:* |
| luxsoft | luxcal_web_calendar | < 5.2.3l | cpe:2.3:a:luxsoft:luxcal_web_calendar:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://jvn.jp/en/jp/JVN04876736/ | Third Party Advisory |
| https://www.luxsoft.eu/ | Product |
| https://www.luxsoft.eu/?download | Product |