CVE-2026-115481: baserCMS: BcCustomContent file fields can be configured to allow executable file extensions such as php, leading to arbitrary PHP file upload

High severity · published Oct 23, 2026

CVE-2026-115481

baserCMS: BcCustomContent file fields can be configured to allow executable file extensions such as php, leading to arbitrary PHP file upload

New

8.5

CVSS

0.3%

EPSS

On KEV

Description

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.

Exploitation

Is it being used?

Exploit prediction (EPSS)0.3% · higher than 27% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

basercms · baserproject

>= 5.0.0-beta1, < 5.3.2; >= 5.4.0, < 5.4.2 · source: vendor

Affected product

basercms