XSS in Wintercms Winter
CVE-2026-125338
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published .
CVSS v3 metric
CVSS v3 base score 4.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Wintercms Winter — versions < 1.2.14
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-125338?
- CVE-2026-125338 is a medium-severity vulnerability in Wintercms Winter, classified under Cross-site Scripting. CVSS score: 4.5/10. Published 2026-11-10.
- How severe is CVE-2026-125338?
- Medium severity. CVSS v3 base score is 4.5 out of 10.