Path traversal in baserCMS - CVE-2026-30940
Published: April 27, 2026
Vulnerability identifier: #VU128065
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-30940
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: baserproject
Affected software:
baserCMS
baserCMS
Detailed vulnerability description
The vulnerability allows a remote user to execute arbitrary code.
The vulnerability exists due to path traversal in the theme file management API endpoint /baser/api/admin/bc-theme-file/theme_files/add.json when processing the path parameter in file creation requests. A remote privileged user can send a specially crafted API request with ../ sequences to write a php file outside the theme directory and execute arbitrary code.
Direct exploitation requires API access, such as when USE_CORE_ADMIN_API=true.
How to mitigate CVE-2026-30940
Install security update from vendor's website.