CVE-2026-27591
Winter: Privilege escalation by authenticated backend users
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Critical10.0 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | Critical9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.78% · top 44% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 10.0.
Weakness
- CWE-284: Improper Access Control (opens in a new tab)All about CWE-284 and its CVEs
- CWE-639: Authorization Bypass Through User-Controlled Key (opens in a new tab)All about CWE-639 and its CVEs
- CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes (opens in a new tab)All about CWE-915 and its CVEs
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Packagistwinter/wn-backend-moduleGHSA-pgpf-m8m4-6cg6 (opens in a new tab)
References (4)
- https://github.com/wintercms/winter/security/advisories/GHSA-pgpf-m8m4-6cg6 (opens in a new tab)x_refsource_CONFIRM
- https://wintercms.com/releases/v1.0.477 (opens in a new tab)x_refsource_MISC
- https://wintercms.com/releases/v1.1.12 (opens in a new tab)x_refsource_MISC
- https://wintercms.com/releases/v1.2.12 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-pgpf-m8m4-6cg6 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-27591)Record last updated .