CMS Made Simple up to 2.2.21 User Management admin/listusers.php Message cross site scripting

Summaryinfo

A vulnerability classified as problematic was found in CMS Made Simple up to 2.2.21. The affected element is an unknown function of the file admin/listusers.php of the component User Management Module. Executing a manipulation of the argument Message can lead to cross site scripting. This vulnerability appears as CVE-2026-4225. The attack may be performed from remote. In addition, an exploit is available.

Detailsinfo

A vulnerability has been found in CMS Made Simple up to 2.2.21 and classified as problematic. This vulnerability affects an unknown function of the file admin/listusers.php of the component User Management Module. The manipulation of the argument message with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect integrity.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-4225. The exploitation appears to be easy. The attack can be initiated remotely. Additional levels of successful authentication are necessary for exploitation. Successful exploitation requires user interaction by the victim. Technical details and also a public exploit are known. The MITRE ATT&CK project declares the attack technique as T1059.007.

It is possible to download the exploit at github.com. It is declared as proof-of-concept. By approaching the search of inurl:admin/listusers.php it is possible to find vulnerable targets with Google Hacking.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-12366). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Content Management System

Name

• CMS Made Simple

Version

• 2.2.0
• 2.2.1
• 2.2.2
• 2.2.3
• 2.2.4
• 2.2.5
• 2.2.6
• 2.2.7
• 2.2.8
• 2.2.9
• 2.2.10
• 2.2.11
• 2.2.12
• 2.2.13
• 2.2.14
• 2.2.15
• 2.2.16
• 2.2.17
• 2.2.18
• 2.2.19
• 2.2.20
• 2.2.21

License

• open-source

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Submitinfo

Accepted

• Submit #770530: cms made simple 2.2.21 XSS (by feioklucy)

Once again VulDB remains the best source for vulnerability data.

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