CVE-2026-30940CWE-22CWE-73

baserCMS: Path Traversal in Theme File API Leads to Arbitrary File Write and RCE

High · published March 31, 2026

CVSS v3.1
7.2
EPSS
1%
Percentile
64.9
In the wild
Unconfirmed
What it is

baserCMS is a website development framework. Prior to version 5.2.3, a path traversal vulnerability exists in the theme file management API (/baser/api/admin/bc-theme-file/theme_files/add.json) that allows arbitrary file write. An authenticated administrator can include ../ sequences in the path parameter to create a PHP file in an arbitrary directory outside the theme directory, which may result in remote code execution (RCE). This issue has been patched in version 5.2.3.

The record
Technical detail
CVSS v3.1
7.2 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.01081 · 64.9th percentile
Weaknesses
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'); CWE-73 · External Control of File Name or Path
Published
2026-03-31T00:45Z
EPSS history
Timeline
  • 31 MAR 00:45Z
    baserCMS: Path Traversal in Theme File API Leads to Arbitrary File Write and RCE
    cvelistv5