CVE-2026-34566: CI4MS Cross-Site Scripting Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-458r-h248-29c5",
  "modified" : "2026-04-06T17:14:26Z",
  "published" : "2026-04-01T22:06:28Z",
  "aliases" : [ "CVE-2026-34566" ],
  "summary" : "CI4MS: Pages Management Full Account Takeover for All-Roles & Privilege-Escalation via Stored DOM XSS",
  "details" : "## Summary\n### **Vulnerability: Stored DOM XSS via Page Management Fields (Persistent Payload Injection)**\n- Stored Cross-Site Scripting via Unsanitized Page Creation and Editing Inputs\n\n### Description\nThe application fails to properly sanitize user-controlled input within the **Page Management** functionality when creating or editing pages. Multiple input fields accept attacker-controlled JavaScript payloads that are stored server-side.\n\nThese stored values are later rendered without proper output encoding across administrative page lists and public-facing page views, leading to stored DOM-based cross-site scripting (XSS).\n\n### Affected Functionality\n- Page creation functionality\n- Page editing functionality\n- Page list and management views\n- Public-facing page rendering\n- Storage and retrieval of page-related data\n\n### Affected Fields\n- Title\n- URL\n- Content\n- Cover Image\n- Image URL\n- Image Width\n- Image Height\n- SEO Description\n- SEO Keywords\n\n### Attack Scenario\n- An attacker creates or edits a page and injects a malicious XSS payload into one or more page-related input fields.\n- The application stores these values without sanitization or encoding.\n- The payload is rendered in administrative page lists and public-facing page views.\n- The payload executes automatically in the browser context of administrators, authenticated users, and unauthenticated visitors.\n\n### Impact\n- Persistent Stored XSS\n- Execution of arbitrary JavaScript in victims’ browsers\n- Privilege escalation when viewed by administrators or privileged users\n- Full administrator account takeover\n- Full account takeover across all roles\n- Full compromise of the entire application\n\nEndpoints:\n- `/backend/pages/create`\n- Page list management view\n- Public-facing page views\n\n## Steps To Reproduce (POC)\n1. Navigate to the Page Management -> Add Page interface\n2. Insert an XSS payload into any page-related field such as:\n`<img src=x onerror=alert(document.domain)>`\n3. Save or publish the page\n4. View the page via the administrative page list or public-facing page\n5. Observe the XSS payload executing automatically\n\n## Remediation\n\n- **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.\n\n- **Apply output encoding:** Implement HTML entity encoding on all user-controlled data before rendering it in the browser. This helps neutralize potentially malicious input.\n\n- **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.\n\n- **Enforce security headers and cookie attributes:**\n  - **Content Security Policy (CSP):** Define and enforce a strict CSP to limit the execution of unauthorized scripts.\n  - **HttpOnly flag:** Set the `HttpOnly` attribute on session cookies to prevent client-side script access.\n  - **SameSite attribute:** Configure the `SameSite` cookie attribute to mitigate Cross-Site Request Forgery (CSRF) risks.\n  - **Secure flag:** Ensure all cookies are transmitted only over HTTPS by enabling the `Secure` attribute.\n\n  These measures collectively reduce the impact of XSS and help prevent escalation paths such as CSRF via XSS.\n\n# Ready Video POC:\nhttps://mega.nz/file/iAkWAKQY#hCUv4DlMPFykPvb4gO94ZVGj64tpUk99gLxE6u1kASk",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "ci4-cms-erp/ci4ms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.31.0.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.28.6.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/ci4-cms-erp/ci4ms/security/advisories/GHSA-458r-h248-29c5"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-34566"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ci4-cms-erp/ci4ms"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ci4-cms-erp/ci4ms/releases/tag/0.31.0.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-01T22:06:28Z",
    "nvd_published_at" : "2026-04-01T22:16:20Z"
  }
}