Stored cross-site scripting vulnerability exists in GroupSession Free edition prior to ver5.3.0, GroupSession byCloud prior to ver5.3.3, and GroupSession ZION prior to ver5.3.2. If a user accesses a crafted page or URL, an arbitrary script may be executed on the web browser of the user.
Conclusion & alert: CVE-2025-54407 is rated Low Risk (22.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). 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 | 2026-05-06 | 0.05% | 0.02% | -0.03% |
| 2 | 2026-04-13 | 0.03% | 0.05% | +0.02% |
| 3 | 2025-12-12 | — | 0.03% | — |
Full EPSS history (3 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.1 | 4.0 | MEDIUM |
|
— | — | [email protected] |
| 6.1 | 3.0 | MEDIUM |
|
2.8 | 2.7 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| groupsession | groupsession | < 5.3.0 | cpe:2.3:a:groupsession:groupsession:*:*:*:*:free:*:*:* |
| groupsession | groupsession | < 5.3.2 | cpe:2.3:a:groupsession:groupsession:*:*:*:*:zion:*:*:* |
| groupsession | groupsession | < 5.3.3 | cpe:2.3:a:groupsession:groupsession:*:*:*:*:bycloud:*:*:* |
| URL | Tags |
|---|---|
| https://groupsession.jp/info/info-news/security20251208 | Vendor Advisory |
| https://jvn.jp/en/jp/JVN19940619/ | Third Party Advisory |