Cross-site Scripting (XSS)

Overview Affected versions of this package are vulnerable to Cross-site Scripting XSS in the renderCss process. An attacker can inject malicious scripts by providing crafted custom styles through the editor settings interface, which are then rendered on backend pages. This is only exploitable if...

Winter: Stored XSS through Editor Settings custom styles

Impact Authenticated Backend Users with the backend.manageeditor "Manage editor settings" permission can provide custom styles through Settings → Editor Settings → Markup Styles that are compiled through the LESS CSS parser and rendered on every backend page. Previously, the compiled output was n...

Winter: Stored XSS through Brand Settings custom styles

Impact Users with the backend.managebranding "Customize the back-end" permission can provide custom CSS through Settings → Customize Backend → Styles that is compiled through the LESS CSS parser and rendered on every backend page. Previously, the compiled output was not sanitized, which could hav...

PT-2026-76556

Name of the Vulnerable Software and Affected Versions Winter CMS versions prior to 1.2.13 Description An issue exists where the backend fails to validate the handler name submitted via the handler POST field during form postbacks. While AJAX requests are validated against the onA-Zw+ pattern, the...

PT-2026-76552

Name of the Vulnerable Software and Affected Versions Winter versions prior to 1.2.13 Description Custom CSS provided through the Brand Settings Styles field is compiled by the LESS parser and rendered without sanitization on every backend page. This allows a user with the backend.manage branding...

PT-2026-76553

Name of the Vulnerable Software and Affected Versions Winter versions 1.2.10 through 1.2.12 Description Authenticated backend users with the backend.manage editor permission can store custom Markup Styles via Settings → Editor Settings → Markup Styles. These styles are compiled by the LESS parser...

PT-2026-76554

Name of the Vulnerable Software and Affected Versions Winter CMS versions prior to 1.2.13 Description Theme Editor AJAX handlers in the CMS section do not enforce per-template-type permission checks. While the CMS controller CmsControllersIndex uses OR-logic across five permissions cms.manage...

The threat to critical infrastructure has changed. Has your readiness?

Critical infrastructure CI organizations underpin national security, public safety, and the economy. In 2026, the cyber threat landscape facing these sectors is structurally different than it was even two years ago. What Microsoft Threat Intelligence is observing across critical infrastructure...

The threat to critical infrastructure has changed. Has your readiness?

Critical infrastructure CI organizations underpin national security, public safety, and the economy. In 2026, the cyber threat landscape facing these sectors is structurally different than it was even two years ago. What Microsoft Threat Intelligence is observing across critical infrastructure...

CVE-2026-27591

Winter is a free, open-source content management system CMS based on the Laravel PHP framework. Prior to 1.0.477, 1.1.12, and 1.2.12, Winter CMS allowed authenticated backend users to escalate their accounts level of access to the system by modifying the roles / permissions assigned to their...

PT-2026-25530

Name of the Vulnerable Software and Affected Versions Winter CMS affected versions not specified Description A security issue was identified in a Winter CMS plugin. The issue allows for unauthorized access or manipulation of the system, though specific details are not provided. No information is...

Winter vulnerable to privilege escalation by authenticated backend users

Impact Affected versions of Winter CMS allowed authenticated backend users to escalate their accounts level of access to the system by modifying the roles / permissions assigned to their account through specially crafted requests to the backend while logged in. To actively exploit this security...

EUVD-2026-11406

Winter vulnerable to privilege escalation by authenticated backend users...

GHSA-PGPF-M8M4-6CG6 Winter vulnerable to privilege escalation by authenticated backend users

Impact Affected versions of Winter CMS allowed authenticated backend users to escalate their accounts level of access to the system by modifying the roles / permissions assigned to their account through specially crafted requests to the backend while logged in. To actively exploit this security...

Authorization Bypass Through User-Controlled Key

Overview Affected versions of this package are vulnerable to Authorization Bypass Through User-Controlled Key via the backend account management in FormController. An attacker can gain unauthorized access to higher privilege levels by sending specially crafted requests while authenticated as a...

CVE-2026-27591

Winter is a free, open-source content management system CMS based on the Laravel PHP framework. Prior to 1.0.477, 1.1.12, and 1.2.12, Winter CMS allowed authenticated backend users to escalate their accounts level of access to the system by modifying the roles / permissions assigned to their...

CVE-2026-27591

Winter is a free, open-source content management system CMS based on the Laravel PHP framework. Prior to 1.0.477, 1.1.12, and 1.2.12, Winter CMS allowed authenticated backend users to escalate their accounts level of access to the system by modifying the roles / permissions assigned to their...

CVE-2026-27591 Winter: Privilege escalation by authenticated backend users

Winter is a free, open-source content management system CMS based on the Laravel PHP framework. Prior to 1.0.477, 1.1.12, and 1.2.12, Winter CMS allowed authenticated backend users to escalate their accounts level of access to the system by modifying the roles / permissions assigned to their...

CVE-2026-27591

CVE-2026-27591 pertains to Winter CMS (Laravel-based). The issue allows authenticated backend users to escalate their own access by mutating roles/permissions via specially crafted backend requests while logged in. Root cause is an authorization weakness in the backend account management flow. Im...

CVE-2026-27591 Winter: Privilege escalation by authenticated backend users

Winter is a free, open-source content management system CMS based on the Laravel PHP framework. Prior to 1.0.477, 1.1.12, and 1.2.12, Winter CMS allowed authenticated backend users to escalate their accounts level of access to the system by modifying the roles / permissions assigned to their...