CVE-2026-125338 is a medium-severity (CVSS 4.5) Cross-site Scripting (XSS) vulnerability. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
Winter CMS is a content management system built on the Laravel PHP framework. Prior to 1.2.14, BrandSetting::renderCss() and EditorSetting::renderCss() store raw LESS compiler output…
Description
Winter CMS is a content management system built on the Laravel PHP framework. Prior to 1.2.14, BrandSetting::renderCss() and EditorSetting::renderCss() store raw LESS compiler output with Cache::forever() but apply strip_tags() only to the value returned on a cache miss. The first render after saving custom CSS appears sanitized while priming an unsafe cache entry, and later cache hits return unsanitized output into the backend style element, allowing a user with backend.manage_branding or backend.manage_editor to cause stored cross-site scripting when another backend page renders the styles. The styles also appear on unauthenticated backend sign-in, password restore, and password reset layouts. This issue is fixed in version 1.2.14.
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
The records we use list no fixed release for CVE-2026-125338. Check the upstream advisory for a patched version, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2026-125338 in your dependencies?
Find it across your dependency tree, including transitive dependencies.