Craft CMS Vulnerable to Stored XSS in Number Prefix & Suffix Fields

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

4.8 · 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 · score source

EPSS

• CVE-2026-25496: 0.42% estimated exploitation activity in the next 30 days; percentile 35.96 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A 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. Proof of Concept Required Permissions - Administrator access - allowAdminChanges is enabled in production, which is against our security recommendations. Steps to Reproduce 1. Log in with an admin account 2. Navigate to Settings → Fields → New field 3. Choose Number as the field type 4. 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" / 5. Save the field 6. Add this field to any element (e.g., User Profile fields via Settings → Users → User Fields) 7. Navigate to your account (/admin/myaccount) or any user profile (/admin/users/{id}) 8. XSS executes when viewing the form <img width="1246" height="677" alt="image-1"…

Published by the source

9 Feb 2026, 20:35 UTC

Last modified by the source

9 Feb 2026, 22:39 UTC

Source last checked

26 Oct 2026, 14:38 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-9f5h-mmq6-2x78

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-25496

Advisory: Craft CMS Vulnerable to Stored XSS in Number Prefix & Suffix Fields
IDs: CVE-2026-25496, GHSA-9f5h-mmq6-2x78
Record: https://patchnext.com/advisories/cve-2026-25496 (revision 1, source checked 26 Oct 2026, 14:38 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: craftcms/cms 5.8.22, 4.16.18. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist craftcms/cms: affected >= 5.0.0-RC1, <= 5.8.21; >= 4.0.0-RC1, <= 4.16.17; fixed in 5.8.22, 4.16.18

## Suggested inspection (read-only)
- Packagist craftcms/cms: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on craftcms/cms.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-9f5h-mmq6-2x78 (GitHub-reviewed advisory GHSA-9f5h-mmq6-2x78 lists affected ranges: Packagist craftcms/cms >=5.0.0-RC1 =4.0.0-RC1 <=4.16.17)

Commands are suggestions: review each one before running it.