CVE-2026-34565: CI4MS Cross-Site Scripting Vulnerability
CRITICALCVE-2026-34565 is a CRITICAL (CVSS 9.1) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting CI4MS libraries in the Packagist ecosystem. The issue involves menu management (posts) full account takeover for all-roles & privilege-escalation via stored dom xss. Remediation is available by upgrading affected packages to version 0.31.0.0.
CVE-2026-34565 at a Glance
Security Impact
CVSS: 9.1
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L).
How to Fix CVE-2026-34565
To remediate this vulnerability, upgrade all affected CI4MS dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade ci4-cms-erp/ci4ms to 0.31.0.0
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for ci4-cms-erp/ci4ms
How to Check if You Are Affected
To determine whether your application is affected by CVE-2026-34565, inspect your project dependencies for CI4MS:
inspect dependencies for ci4-cms-erp/ci4ms
Analyze the terminal output to locate any version of CI4MS in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.31.0.0), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where 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. In CI4MS, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-34565 Affected CI4MS Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
ci4-cms-erp/ci4ms
|
Packagist |
< 0.31.0.0
|
0.31.0.0
|
References
Frequently Asked Questions
What is CVE-2026-34565?
Which CI4MS versions are affected?
What version fixes CVE-2026-34565?
Is ci4-cms-erp/ci4ms affected?
What is the CVSS score of CVE-2026-34565?
What CWE is associated with CVE-2026-34565?
How can I check Packagist dependencies for CVE-2026-34565?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-xgh5-w62m-8mpr",
"modified" : "2026-04-06T17:14:22Z",
"published" : "2026-04-01T22:05:45Z",
"aliases" : [ "CVE-2026-34565" ],
"summary" : "CI4MS: Menu Management (Posts) Full Account Takeover for All-Roles & Privilege-Escalation via Stored DOM XSS",
"details" : "## Summary\n### **Vulnerability: Stored DOM XSS via Posts Added to Menu (Persistent Payload Injection)**\n- Stored Cross-Site Scripting via Unsafe Rendering of Post Entries in Menu Management\n\n### Description\nThe application fails to properly sanitize user-controlled input when **adding Posts to navigation menus** through the Menu Management functionality. Post-related data selected via the Posts section is stored server-side and rendered without proper output encoding.\n\nThese stored values are later rendered unsafely within administrative dashboards and public-facing navigation menus, resulting in stored DOM-based cross-site scripting (XSS).\n\n### Affected Functionality\n- Menu Management – Posts section\n- Adding posts to navigation menus\n- Menu storage and rendering logic\n\n### Attack Scenario\n- An attacker creates or controls a post containing a malicious JavaScript payload.\n- The attacker adds the post to the menu using the **Posts** functionality in Menu Manager.\n- The application stores the menu entry without sanitization or encoding.\n- The payload persists and executes whenever the menu is rendered.\n\n### Impact\n- Persistent Stored DOM XSS\n- Execution of arbitrary JavaScript in victims’ browsers\n- Privilege escalation in administrative contexts\n- Full administrator account takeover\n- Full account takeover across all roles\n- Full compromise of the entire application via global navigation execution\n\nEndpoint:\n- `/backend/menu/`\n\n## Steps To Reproduce (POC)\n1. Navigate to Menu Management\n2. Use the **Posts** section to add a post containing an XSS payload such as:\n`<img src=x onerror=alert(document.domain)>`\n3. Save the menu\n4. View the menu in the administrative panel or any public-facing page\n5. Observe the JavaScript 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/PcMiUA5K#L2RlZJa340Q8K42TksxiXMuo_9XsRYPi14-WvBnak2A",
"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-xgh5-w62m-8mpr"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-34565"
}, {
"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" : "2026-04-01T22:05:45Z",
"nvd_published_at" : "2026-04-01T22:16:20Z"
}
}