What is CVE-2026-27591?

CVE-2026-27591 is a critical-severity vulnerability in Wintercms Winter, classified under Improper Access Control. CVSS score: 10.0/10. Published 2026-03-11.

How severe is CVE-2026-27591?

Critical severity. CVSS v3 base score is 10.0 out of 10.

Auth bypass in Wintercms Winter

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…

EPSS: 0.001 (28.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

Affected products

Wintercms Winter — versions >= 1.2.0, < 1.2.12, >= 1.1.0, < 1.1.12, < 1.0.477

Weakness classification (CWE)

References

https://github.com/wintercms/winter/security/advisories/GHSA-pgpf-m8m4-6cg6 (x_refsource_CONFIRM)
https://wintercms.com/releases/v1.0.477 (x_refsource_MISC)
https://wintercms.com/releases/v1.1.12 (x_refsource_MISC)
https://wintercms.com/releases/v1.2.12 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-27591?: CVE-2026-27591 is a critical-severity vulnerability in Wintercms Winter, classified under Improper Access Control. CVSS score: 10.0/10. Published 2026-03-11.
How severe is CVE-2026-27591?: Critical severity. CVSS v3 base score is 10.0 out of 10.