CVE-2026-25491: Craftcms/cms Cross-Site Scripting Vulnerability

LOW
Advisory Identifier: GHSA-7pr4-wx9w-mqwr
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CWE-79
Published
Advisory Summary

CVE-2026-25491 is a LOW cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Craftcms/cms libraries in the Packagist ecosystem. The issue involves craft cms vulnerable to stored xss in entry types name. Remediation is available by upgrading affected packages to version 5.8.22.

CVE-2026-25491 at a Glance

CVE Identifier CVE-2026-25491
GHSA Identifier GHSA-7pr4-wx9w-mqwr
Severity LOW
CVSS v3.1 Base Score N/A
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Craftcms/cms
Package Ecosystem Packagist
Published Date
Last Updated

How to Fix CVE-2026-25491

To remediate this vulnerability, upgrade all affected Craftcms/cms dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

craftcms/cms fixed: 5.8.22 
Upgrade craftcms/cms to 5.8.22
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for craftcms/cms

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-25491, inspect your project dependencies for Craftcms/cms:

inspect dependencies for craftcms/cms

Analyze the terminal output to locate any version of Craftcms/cms in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.8.22), 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 Craftcms/cms, 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

## Summary Stored XSS via Entry Type names. The name is not sanitized when displayed in the Entry Types list. --- ## Proof of Concept ### Required Permissions (Attacker) - Admin access (only admins have access to the settings page) - `allowAdminChanges` is enabled in production, which is against our [security recommendations](https://craftcms.com/knowledge-base/securing-craft). ### Steps to Reproduce 1. Log in as an attacker. 2. Go to **Settings** -> **Entry Types** (`/admin/settings/entry-types`). 3. Create a new Entry Type. 4. Set **Name** to: ```html <img src=x onerror="alert('XSS-EntryTypes')" hidden> ``` 5. Save the Entry Type, and you’ll be redirected back to the entry types table automatically. 6. Notice the alert fires when the entry types table renders.

CVE-2026-25491 Affected Craftcms/cms Versions

1 component(s)
Fixed Versions:
5.8.22
Product / Package Ecosystem Affected Versions Fixed Version
craftcms/cms
 Packagist
≥ 5.0.0-RC1
< 5.8.22
5.8.22

References

GitHub Advisory / Wiki ADVISORY
https://github.com/craftcms/cms/security/advisories/GHSA-7pr4-wx9w-mqwr
NVD — CVE-2026-25491 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25491
Security Fix Commit FIX COMMIT
https://github.com/craftcms/cms/commit/cfd6ba0e2ce1a59a02d75cae6558c4ace1ab8bd4
Craftcms/cms Source Repository REPOSITORY
https://github.com/craftcms/cms
Craftcms/cms Release RELEASE
https://github.com/craftcms/cms/releases/tag/5.8.22

Frequently Asked Questions

What is CVE-2026-25491?
CVE-2026-25491 is a security vulnerability in Craftcms/cms involving Craft CMS Vulnerable to Stored XSS in Entry Types Name under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Craftcms/cms versions are affected?
Affected versions include releases prior to 5.8.22 across affected packages: craftcms/cms.
What version fixes CVE-2026-25491?
Upgrading to 5.8.22 (or the latest patched release for your respective branch) resolves the vulnerability.
Is craftcms/cms affected?
Yes, craftcms/cms is affected in releases prior to 5.8.22. Upgrade your dependency to 5.8.22 or later.
What CWE is associated with CVE-2026-25491?
CVE-2026-25491 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (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.).
How can I check Packagist dependencies for CVE-2026-25491?
Run the dependency tree command: 'inspect dependencies for craftcms/cms'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-7pr4-wx9w-mqwr",
  "modified" : "2026-02-09T22:38:18Z",
  "published" : "2026-02-09T20:35:10Z",
  "aliases" : [ "CVE-2026-25491" ],
  "summary" : "Craft CMS Vulnerable to Stored XSS in Entry Types Name",
  "details" : "## Summary\n\nStored XSS via Entry Type names. The name is not sanitized when displayed in the Entry Types list.\n\n---\n## Proof of Concept\n\n### Required Permissions (Attacker)\n\n- Admin access (only admins have access to the settings page)\n- `allowAdminChanges` is enabled in production, which is against our [security recommendations](https://craftcms.com/knowledge-base/securing-craft).\n\n### Steps to Reproduce\n1. Log in as an attacker.\n2. Go to **Settings** -> **Entry Types** (`/admin/settings/entry-types`).\n3. Create a new Entry Type.\n4. Set **Name** to:\n```html\n<img src=x onerror=\"alert('XSS-EntryTypes')\" hidden>\n```\n5. Save the Entry Type, and you’ll be redirected back to the entry types table automatically.\n6. Notice the alert fires when the entry types table renders.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "craftcms/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.0.0-RC1"
      }, {
        "fixed" : "5.8.22"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 5.8.21"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/security/advisories/GHSA-7pr4-wx9w-mqwr"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-25491"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/commit/cfd6ba0e2ce1a59a02d75cae6558c4ace1ab8bd4"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/craftcms/cms"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/releases/tag/5.8.22"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-09T20:35:10Z",
    "nvd_published_at" : "2026-02-09T20:15:57Z"
  }
}