CVE-2026-25496: Craftcms/cms Cross-Site Scripting Vulnerability
MODERATECVE-2026-25496 is a MODERATE 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 number prefix & suffix fields. Remediation is available by upgrading affected packages to version 5.8.22, 4.16.18.
CVE-2026-25496 at a Glance
How to Fix CVE-2026-25496
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.
Upgrade craftcms/cms to 5.8.22Upgrade craftcms/cms to 4.16.18Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for craftcms/cmsHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-25496, inspect your project dependencies for Craftcms/cms:
inspect dependencies for craftcms/cmsAnalyze 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
CVE-2026-25496 Affected Craftcms/cms Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
craftcms/cms
|
Packagist |
≥ 5.0.0-RC1
< 5.8.22
|
5.8.22
|
|
craftcms/cms
|
Packagist |
≥ 4.0.0-RC1
< 4.16.18
|
4.16.18
|
References
Frequently Asked Questions
What is CVE-2026-25496?
Which Craftcms/cms versions are affected?
What version fixes CVE-2026-25496?
Is craftcms/cms affected?
What CWE is associated with CVE-2026-25496?
How can I check Packagist dependencies for CVE-2026-25496?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-9f5h-mmq6-2x78",
"modified" : "2026-02-09T22:39:05Z",
"published" : "2026-02-09T20:35:47Z",
"aliases" : [ "CVE-2026-25496" ],
"summary" : "Craft CMS Vulnerable to Stored XSS in Number Prefix & Suffix Fields",
"details" : "## Summary\n\nA stored XSS vulnerability exists in the Number field type settings. The Prefix and Suffix fields are rendered using the `|md|raw` Twig filter without proper escaping, allowing script execution when the Number field is displayed on users' profiles.\n\n## Proof of Concept\n\n### Required Permissions\n\n- Administrator access\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 with an admin account\n2. Navigate to **Settings** → **Fields** → **New field**\n3. Choose **Number** as the field type\n4. Set the **Prefix/Suffix Text** field to: <img width=\"611\" height=\"908\" alt=\"image\" src=\"https://github.com/user-attachments/assets/63766ca4-4fa9-490b-8bea-37364137527d\" />\n```html\n<img src=x onerror=\"alert('Number Prefix/Suffix XSS')\" hidden>\n```\n5. Save the field\n6. Add this field to any element (e.g., User Profile fields via **Settings** → **Users** → **User Fields**)\n7. Navigate to your account (`/admin/myaccount`) or any user profile (`/admin/users/{id}`)\n8. XSS executes when viewing the form <img width=\"1246\" height=\"677\" alt=\"image-1\" src=\"https://github.com/user-attachments/assets/dafeb2b7-905f-4a4b-b3d6-1c16a905498f\" />\n\n## Mitigation\nSanitize prefix/suffix before rendering or use `|e` filter instead of `|raw`.",
"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"
} ],
"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"
}
}, {
"package" : {
"ecosystem" : "Packagist",
"name" : "craftcms/cms"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "4.0.0-RC1"
}, {
"fixed" : "4.16.18"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 4.16.17"
}
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/craftcms/cms/security/advisories/GHSA-9f5h-mmq6-2x78"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-25496"
}, {
"type" : "WEB",
"url" : "https://github.com/craftcms/cms/commit/cb5fb0e979e72f315c9178fc031883d49527f513"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/craftcms/cms"
}, {
"type" : "WEB",
"url" : "https://github.com/craftcms/cms/releases/tag/4.16.18"
}, {
"type" : "WEB",
"url" : "https://github.com/craftcms/cms/releases/tag/5.8.22"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-79" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-02-09T20:35:47Z",
"nvd_published_at" : "2026-02-09T20:15:58Z"
}
}