CVE-2026-115481: CWE-434: Unrestricted Upload of File with Dangerous Type in baserproject basercms
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.
CVSS v4.0
Score 8.5high
Affected software
baserproject
basercms
pkg:github/baserproject/basercmsRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
baserCMS is affected by an unrestricted file upload vulnerability (CWE-434) due to the PermissionGroupsService::build() method behavior. When a plugin's config/permission.php file is missing, the service writes a wildcard allow rule granting broad access to non-admin groups. The BcCustomContent plugin lacks this file, resulting in the operators group being able to store and execute arbitrary PHP files under the web root. This vulnerability is present in versions >=5.0.0-beta1 <5.3.2 and >=5.4.0 <5.4.2 and is fixed in versions 5.3.2 and 5.4.2.
Potential Impact
An authenticated user in the operators group can upload and execute arbitrary PHP code on the server, leading to potential full server compromise. This elevates privileges and allows execution of malicious code within the web server context.
Mitigation Recommendations
Upgrade baserCMS to version 5.3.2 or later if using the 5.0.0-beta1 to 5.3.2 range, or to version 5.4.2 or later if using the 5.4.0 to 5.4.2 range. These versions contain official fixes that address the improper permission configuration handling and prevent arbitrary code execution.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-10-22T15:06:52.738Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6adb651b4d27ba8daa2e068c
Added to database: 10/23/2026, 13:46:03 UTC
Last enriched: 10/23/2026, 14:00:36 UTC
Last updated: 10/23/2026, 15:26:05 UTC
Views: 6
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