Arbitrary file upload in Baserproject Basercms
CVE-2026-115481
baserCMS is a website development framework. Starting in version 5.0.0-beta1 and prior to versions 5.3.2 and 5.4.2, `PermissionGroupsService::build()` reads a plugin's `config/permission.php` to decide what each user group may reach. When that file is absent it writes a wildcard allow rule instead: `url` `/baser/<prefix>/<plugin>/*`, `method` `*`, `auth` true, for every non-admin group. BcCustomContent has no such file in any release. After an administrator installs it, the default `operators` group can store and execute arbitrary PHP under the document root. Versions 5.3.2 and 5.4.2 patch the issue.
Vulnerability class: Unrestricted File Upload
Published · last modified .
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Baserproject Basercms — versions >= 5.0.0-beta1, < 5.3.2, >= 5.4.0, < 5.4.2
Weakness classification (CWE)
References
- github.com/baserproject/basercms/security/advisories/GHSA-8jrp-4h7c-m679
- github.com/baserproject/basercms/commit/2ed19c878add5c26fc765572e0e77173c1f1fdb5
- github.com/baserproject/basercms/commit/b0ef31b10dc6267b48ebc9a80d34bc7c4c09c311
- github.com/baserproject/basercms/releases/tag/5.3.2
- github.com/baserproject/basercms/releases/tag/5.4.2