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

Q: Which deployments are exposed?

Deployments running versions from 5.0.0-beta1 up to, but not including, 5.3.2 or 5.4.2 are affected if an administrator has installed BcCustomContent. The plugin lacks a config/permission.php file in every release, causing the fallback wildcard permission to be created for non-admin groups.

Q: What access does an attacker need?

An attacker needs access through a non-admin user group that receives the fallback permission, such as the default operators group. That access can then be used to store and execute arbitrary PHP files under the document root.

Q: Is the default operators group affected?

Yes. After an administrator installs BcCustomContent, the default operators group receives the wildcard allow rule and can store and execute arbitrary PHP under the document root on affected versions.

Q: What versions contain the fix?

The issue is patched in baserCMS versions 5.3.2 and 5.4.2.

Published Oct 23, 2026

Updated

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.

Affected Software

1 affected component

baserCMS BaserCMS>=5.0.0-beta1<5.3.2, >=5.0.0-beta1<5.4.2

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade baserCMS to a version that resolves this vulnerability.
Fixed in 5.3.2
Upgrade
Upgrade baserCMS to a version that resolves this vulnerability.
Fixed in 5.4.2

Event History

Oct 23, 2026

CVE Published

via MITRE·01:34 PM

Data Sourced

via MITRE·01:34 PM

DescriptionWeakness

Frequently Asked Questions

Which deployments are exposed?

Deployments running versions from 5.0.0-beta1 up to, but not including, 5.3.2 or 5.4.2 are affected if an administrator has installed BcCustomContent. The plugin lacks a config/permission.php file in every release, causing the fallback wildcard permission to be created for non-admin groups.

What access does an attacker need?

An attacker needs access through a non-admin user group that receives the fallback permission, such as the default operators group. That access can then be used to store and execute arbitrary PHP files under the document root.

Is the default operators group affected?

Yes. After an administrator installs BcCustomContent, the default operators group receives the wildcard allow rule and can store and execute arbitrary PHP under the document root on affected versions.

What versions contain the fix?

The issue is patched in baserCMS versions 5.3.2 and 5.4.2.

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

Affected Software

Remediation

Event History

Frequently Asked Questions

Which deployments are exposed?

What access does an attacker need?

Is the default operators group affected?

What versions contain the fix?

Company

Resources

Contact

Frequently Asked Questions

Which deployments are exposed?

What access does an attacker need?

Is the default operators group affected?

What versions contain the fix?