GHSA-pgpf-m8m4-6cg6 · Severity: critical · Ecosystem: composer — Winter vulnerable to 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 account through specially crafted requests to the backend while logged in. To actively exploit this security issue, an attacker would need access to the Backend with a user account with any level of access. This vulnerability is fixed in 1.0.477, 1.1.12, and 1.2.12.
Conclusion & alert: CVE-2026-27591 is rated Moderate Risk (45.6/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.06%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-03-12 | — | 0.06% | — |
Full EPSS history (1 record total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.9 | 3.1 | CRITICAL |
|
3.1 | 6.0 | [email protected] |
GHSA-pgpf-m8m4-6cg6 · Severity: critical · Ecosystem: composer — Winter vulnerable to privilege escalation by authenticated backend users
| URL | Tags |
|---|---|
| https://github.com/wintercms/winter/security/advisories/GHSA-pgpf-m8m4-6cg6 | Patch Vendor Advisory |
| https://wintercms.com/releases/v1.0.477 | Release Notes |
| https://wintercms.com/releases/v1.1.12 | Release Notes |
| https://wintercms.com/releases/v1.2.12 | Release Notes |