CVE-2026-34562

Vulnerability: Stored DOM XSS via System Settings, Company Information (Same-Page Attribute Breakout & Persistent Payload Injection)

• Stored Cross-Site Scripting via Unsanitized Company Information Configuration Fields with Immediate Same-Page Execution

Description

The application fails to properly sanitize user-controlled input within System Settings, Company Information. Several administrative configuration fields accept attacker-controlled input that is stored server-side and later rendered without proper output encoding.

Affected fields include, but are not limited to:

1. Company Name
2. Slogan
3. Company Phone
4. Company Mobile
5. Company Email
6. Google Maps iframe link
7. Company Logo and other media-related fields

Unlike the public-facing landing page injection vulnerability, this issue executes directly on the same settings page. The injected payload breaks out of the HTML attribute context and is immediately interpreted by the browser when rendered, resulting in same-page DOM-based stored XSS.

This represents different functionality and a separate vulnerability from public-facing rendering.

Affected Functionality

• System Settings, Company Information configuration
• Same-page rendering of user-controlled input fields
• DOM attribute injection within form inputs
• Storage and retrieval of company information values

Attack Scenario

• An attacker injects a malicious JavaScript payload into one or more Company Information fields.
• The payload breaks out of the HTML attribute context.
• The application stores and re-renders the payload without sanitization or encoding.
• The payload executes immediately on the same settings page.
• The script executes in the browser context of the authenticated user managing settings.

Steps To Reproduce (POC)

1. Navigate to System Settings -> Company Information
2. Insert the following XSS payload into any Company Information field:
   test"><img src=1 onerror=alert()>" class="form-control" placeholder="Name" required>
3. Save the settings
4. Observe that the payload breaks out of the input attribute context
5. The XSS executes immediately on the same page

Ready Video POC:

https://mega.nz/file/qEcFUIjR#2OKX78JgPQI2x5957GE-vx1zYzJv2a9JqjyBsrRFBkk

• Persistent Stored XSS
• Immediate Same-Page DOM XSS execution
• Execution of arbitrary JavaScript in victims’ browsers
• Administrative privilege escalation
• Full administrator account takeover
• Full account takeover across all roles
• Full compromise of the entire platform

Endpoints:

• /backend/settings/ (Company Information)

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

CVE-2026-34562 has a CVSS score of 4.7 (Medium). The vector is network-reachable, high privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.31.0.0); upgrading removes the vulnerable code path.

Kodem intelligence

• Avoid unsafe DOM manipulation methods: Do not use .html(), innerHTML, or similar sink functions in client-side JavaScript or server-side templating (e.g., PHP). Even when user input flowing into these sinks is not immediately apparent, they can introduce Cross-Site Scripting (XSS) vulnerabilities that an attacker may exploit.

• Apply output encoding: Implement HTML entity encoding on all user-controlled data before rendering it in the browser. This helps neutralize potentially malicious input.

• Implement input sanitization: Ensure that all user-supplied input is properly sanitized before processing or output. Currently, no sanitization mechanisms are in place, which should be addressed as a priority.

• Enforce security headers and cookie attributes:

  • Content Security Policy (CSP): Define and enforce a strict CSP to limit the execution of unauthorized scripts.
  • HttpOnly flag: Set the HttpOnly attribute on session cookies to prevent client-side script access.
  • SameSite attribute: Configure the SameSite cookie attribute to mitigate Cross-Site Request Forgery (CSRF) risks.
  • Secure flag: Ensure all cookies are transmitted only over HTTPS by enabling the Secure attribute.

  These measures collectively reduce the impact of XSS and help prevent escalation paths such as CSRF via XSS.

1. What is CVE-2026-34562? CVE-2026-34562 is a medium-severity cross-site scripting (XSS) vulnerability in ci4-cms-erp/ci4ms (composer), affecting versions <= 0.28.6.0. It is fixed in 0.31.0.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2026-34562? CVE-2026-34562 has a CVSS score of 4.7 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of ci4-cms-erp/ci4ms are affected by CVE-2026-34562? ci4-cms-erp/ci4ms (composer) versions <= 0.28.6.0 is affected.
4. Is there a fix for CVE-2026-34562? Yes. CVE-2026-34562 is fixed in 0.31.0.0. Upgrade to this version or later.
5. Is CVE-2026-34562 exploitable, and should I be worried? Whether CVE-2026-34562 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-34562 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-34562? Upgrade ci4-cms-erp/ci4ms to 0.31.0.0 or later.