CVE-2026-32639
CVE-2026-32639 is a medium-severity vulnerability with a CVSS 3.x base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-289.
Key facts
- Severity: Medium (CVSS 3.x base score 6.8)
- EPSS exploit prediction: 0% (38th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-289
- Published:
- Last modified:
Description
Winter CMS is a content management system built on the Laravel PHP framework. In versions up to and including 1.2.12, the CMS section's Theme Editor AJAX handlers did not enforce per-template-type permission checks, allowing a backend user with any single CMS permission to act on template types outside their authorized scope. The CMS controller gated access to the section as a whole using OR-logic across its five permissions, but individual handlers such as onSave(), onDelete(), and onDeleteTemplates() did not verify that the user held the specific permission for the requested template type, so a user with only cms.manage_pages could craft AJAX requests to delete layouts, modify partials, or read content files. Separately, the AssetList widget was registered for any user who passed the controller gate regardless of the cms.manage_assets permission, and its onUpload() handler omitted the theme-validation call present on the other mutating handlers, permitting unauthorized file uploads into the active theme's asset directory. Exploitation requires an authenticated backend account holding at least one of the CMS Theme Editor permissions. This issue is fixed in version 1.2.13.
Frequently asked questions
- What is CVE-2026-32639?
- Winter CMS is a content management system built on the Laravel PHP framework. In versions up to and including 1.2.12, the CMS section's Theme Editor AJAX handlers did not enforce per-template-type permission checks, allowing a backend user with any single CMS permission to act on template types outside their authorized scope. The CMS controller gated access to the section as a whole using OR-logic across its five permissions, but individual handlers such as onSave(), onDelete(), and onDeleteTemplates() did not verify that the user held the specific permission for the requested template type, so a user with only cms.manage_pages could craft AJAX requests to delete layouts, modify partials, or read content files. Separately, the AssetList widget was registered for any user who passed the controller gate regardless of the cms.manage_assets permission, and its onUpload() handler omitted the theme-validation call present on the other mutating handlers, permitting unauthorized file uploads into the active theme's asset directory. Exploitation requires an authenticated backend account holding at least one of the CMS Theme Editor permissions. This issue is fixed in version 1.2.13.
- How severe is CVE-2026-32639?
- CVE-2026-32639 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2026-32639 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-32639?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2026-32639 published?
- CVE-2026-32639 was published on 2026-08-26 and last updated on 2026-09-09.
References
- https://github.com/wintercms/winter/commit/164c62524e8abc153d09c6c35916278bdb746a2b
- https://github.com/wintercms/winter/commit/5391afa242eba3c476869035b7492e50a262c46b
- https://github.com/wintercms/winter/releases/tag/v1.2.13
- https://github.com/wintercms/winter/security/advisories/GHSA-5c4f-9pq9-6c77
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