GHSA-pgpf-m8m4-6cg6
Winter vulnerable to privilege escalation by authenticated backend users
Quick fix
GHSA-pgpf-m8m4-6cg6 — winter/wn-backend-module: upgrade to the fixed version with the command below.
composer require winter/wn-backend-module:^1.2.12Details
## 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 issue, an attacker would need access to the Backend with a user account with any level of access.
The Winter CMS maintainers strongly recommend that all Winter CMS sites that have any reliance on the roles & permissions system to update immediately. Security fixes have been backported to all major versions of Winter (1.0, 1.1, and 1.2).
## Patches Multiple fixes and defence in depth has been applied to prevent current and future privilege escalation attacks at the lowest level possible.
This security issue has been fixed as of https://wintercms.com/releases/v1.0.477, https://wintercms.com/releases/v1.1.12, https://wintercms.com/releases/v1.2.12.
## Workarounds If you cannot upgrade, you may apply the changes from the releases to your Winter CMS installation manually to resolve this issue.
Are you affected?
Enter the version of the package you're using.
Affected packages
1.2.0Fixed in: 1.2.12composer require winter/wn-backend-module:^1.2.121.1.0Fixed in: 1.1.12composer require winter/wn-backend-module:^1.1.120Fixed in: 1.0.477composer require winter/wn-backend-module:^1.0.477References
- https://github.com/wintercms/winter/security/advisories/GHSA-pgpf-m8m4-6cg6[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2026-27591[ADVISORY]
- https://github.com/wintercms/winter[PACKAGE]
- https://wintercms.com/releases/v1.0.477[WEB]
- https://wintercms.com/releases/v1.1.12[WEB]
- https://wintercms.com/releases/v1.2.12[WEB]