CVE-2026-55872
HighCVSS 8.7Exploitation Probability (EPSS)
Low risk13th percentile - higher than 13% of all known CVEs
Summary
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.
Risk Assessment
An attacker can execute arbitrary script in the administrator's browser, hijack the session, and perform administrative actions, potentially leading to full application takeover.
Recommendation
Upgrade GYM One to version 1.4.1 or later; until then, validate and sanitize input data and monitor for unusual administrator activity.
Other vulnerabilities in GYM One
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS