mayerbalintdev GYM One up to 1.4.0 User List admin/users/index.php cross site scripting

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.0$0-$5k1.23

Summaryinfo

A vulnerability, which was classified as problematic, was found in mayerbalintdev GYM One up to 1.4.0. This vulnerability affects unknown code of the file admin/users/index.php of the component User List. The manipulation results in cross site scripting. This vulnerability is identified as CVE-2026-55872. The attack can be executed remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in mayerbalintdev GYM One up to 1.4.0. Affected is some unknown functionality of the file admin/users/index.php of the component User List. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-55872 since 06/17/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1059.007 by the MITRE ATT&CK project.

By approaching the search of inurl:admin/users/index.php it is possible to find vulnerable targets with Google Hacking.

Upgrading to version 1.4.1 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.1
VulDB Meta Temp Score: 6.0

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.7
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Google Hack: 🔒
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: GYM One 1.4.1

Timelineinfo

06/17/2026 CVE reserved
10/15/2026 +120 days Advisory disclosed
10/15/2026 +0 days VulDB entry created
10/15/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-55872 (🔒)
GCVE (CVE): GCVE-0-2026-55872
GCVE (VulDB): GCVE-100-420786

Entryinfo

Created: 10/15/2026 20:59
Changes: 10/15/2026 20:59 (65)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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