Vulnerability Database

346,508

Total vulnerabilities in the database

Craft CMS Vulnerable to Stored XSS via User Group Name in User Permissions Page — craftcms / cms

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Summary

A stored XSS vulnerability exists in the User Permissions page. The User Group name is rendered without proper HTML escaping in the permissions section, allowing an attacker to execute arbitrary JavaScript when another user views or edits a user's permissions.

> [!NOTE] > This is a separate vulnerability from the previously reported "Stored XSS via User Group Name in User Settings Page" and "Multiple Stored XSS in User Group Edit Page". This affects a different sink: the individual user's permissions page.

Proof of Concept

Required Permissions

Steps to Reproduce

  1. Log in to the control panel as an admin
  2. Navigate to Settings → Users → User Groups
  3. Create or edit a user group and set the Name field to: <img src=x onerror="alert('XSS')" hidden>
  4. Save the user group
  5. Navigate to Users and edit any user (/admin/users/{id})
  6. Click on the Permissions tab
  7. XSS executes

Mitigation

Sanitize user group names when rendering in the user permissions template.

References

https://github.com/craftcms/cms-ghsa-4mgv-366x-qxvx/pull/2

No technical information available.

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.