CVE-2026-55872

GYM One admin user list is vulnerable to stored cross-site scripting

Published Oct 15, 2026 CVSS 3.1 · 8.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Mayerbalintdev
Mayerbalintdev gym-one
Vendors & Products Mayerbalintdev
Mayerbalintdev gym-one
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title GYM One admin user list is vulnerable to stored cross-site scripting
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 8.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Oct 21, 2026, 1:03 AM
Reserved
Jun 17, 2026, 4:44 PM
Status
Deferred
Published
Oct 15, 2026, 7:17 PM
Modified
Oct 21, 2026, 1:17 AM