CVE-2026-34557: CI4MS Cross-Site Scripting Vulnerability
CRITICALCVE-2026-34557 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 permissions management 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-2026-34557 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-2026-34557
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-2026-34557, 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-2026-34557 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-2026-34557?
Which CI4MS versions are affected?
What version fixes CVE-2026-34557?
Is ci4-cms-erp/ci4ms affected?
What is the CVSS score of CVE-2026-34557?
What CWE is associated with CVE-2026-34557?
How can I check Packagist dependencies for CVE-2026-34557?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-rpjr-985c-qhvm",
"modified" : "2026-04-01T00:10:00Z",
"published" : "2026-04-01T00:10:00Z",
"aliases" : [ "CVE-2026-34557" ],
"summary" : "CI4MS: Permissions Management Full Account Takeover for All-Roles & Privilege-Escalation via Stored DOM XSS",
"details" : "## Summary\n### **Vulnerability: Stored DOM XSS via Group / Role Management Fields (Administrative Context Execution)**\n- Stored Cross-Site Scripting via Unsanitized Group / Role Management Inputs\n\n### Description\nThe application fails to properly sanitize user-controlled input within group and role management functionality. Multiple input fields (three distinct group-related fields) can be injected with malicious JavaScript payloads, which are then stored server-side.\n\nThese stored payloads are later rendered unsafely within privileged administrative views without proper output encoding, leading to stored cross-site scripting (XSS) within the role and permission management context.\n\n### Affected Functionality\n- Group creation and editing functionality\n- Role and permission assignment interfaces\n- Storage and retrieval of group-related data\n\n### Attack Scenario\n- An attacker injects a malicious XSS payload into one or more group-related input fields.\n- The application stores these values without sanitization or encoding.\n- An administrator views the group or role management interface.\n- The payload executes automatically in the administrator’s browser.\n\n### Impact\n- Persistent Stored XSS\n- Execution of arbitrary JavaScript in victims’ browsers\n- Privilege escalation when viewed by administrators\n- Full administrator account takeover\n- Full compromise of the entire application\n\nEndpoints:\n- `/backend/users/groupList/`\n\n## Steps To Reproduce (POC)\n1. Navigate to the Group / Role Management page\n2. Insert an XSS payload into any of the three group-related input fields such as:\n`<img src=x onerror=alert(document.domain)>`\n3. Save the group or role changes\n4. View the group/role management page as an administrator\n5. Observe the XSS payload executing automatically\n\n## Remediation\n- Never use .html() again or any innerHTML-style like JS in your PHP, or any other sink, even if user inputs that flow into them are not clear, they still represent real world danger as an attacker can make use of this to exploit the application via XSS. And do HTML Encoding as much as possible and always do Sanitization, theres no sanitization there unfortunately. Also apply CSP, HttpOnly, SameSite, and Secure upon all application, they reduce severity of XSS & escalated-CSRF via XSS and do great jobs\n\n# Ready Video POC:\nhttps://mega.nz/file/6QUEXDbR#JXzYXg9bef_NeSUVFB4R03UeXLtAVtYwTRsdrHLlokU",
"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-rpjr-985c-qhvm"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-34557"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/ci4-cms-erp/ci4ms"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-79" ],
"severity" : "CRITICAL",
"github_reviewed" : true,
"github_reviewed_at" : "2026-04-01T00:10:00Z",
"nvd_published_at" : "2026-03-30T21:17:10Z"
}
}