CVE-2026-55872 Details
Description
GYM One is open-source gym management software for fitness centers, personal trainers, and sports clubs. Prior to 1.4.1, GYM One's admin/users/index.php renders the stored firstname, lastname, and email profile fields into the administrator user list without HTML output encoding. An attacker who can store values in those fields can cause content to execute in an administrator's browser when the administrator visits /admin/users/. The persistent script can access administrator-session data or perform actions with the administrator's privileges until the stored record is removed. This issue is fixed in version 1.4.1.
A stored cross-site scripting vulnerability has been identified in GYM One versions prior to 1.4.1. The issue resides in the admin user management interface, specifically within 'admin/users/index.php'. The vulnerability allows injected scripts to execute in the context of an administrator's browser session. This is made possible because the application fails to properly sanitize and encode user input before displaying it. As a result, an attacker can exploit this flaw by injecting malicious content into their profile, which then executes when an admin views the user list.
The vulnerability has been patched in GYM One version 1.4.1. Users are advised to update to this version. For those who cannot update, the vulnerability can be mitigated by manually sanitizing user-generated output with 'htmlspecialchars()' before rendering it in the admin interface.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 15, 2026CISA-ADP
Assessed Oct 21, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/mayerbalintdev/GYM-One/security/advisories/GHSA-75g9-vp9w-5388 | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/mayerbalintdev/GYM-One/commit/d3a0cf134f0ab3ac12aee7dca283b93c4290dcc4 | [email protected] | Source CodeVendor |
| https://github.com/mayerbalintdev/GYM-One/releases/tag/V1.4.1 | [email protected] | Release NotesVendor |
| https://github.com/mayerbalintdev/GYM-One/security/advisories/GHSA-75g9-vp9w-5388 | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| GYM One | 1.0.0 (semver) |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Oct 21, 2026 | CVE Modified | CISA-ADP |
| Oct 15, 2026 | New CVE Received | [email protected] |