SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-30940

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.

HIGH 7.2EPSS 1.05%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.05%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1
7.2 HIGHCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS
1.05% probability · 62th percentile
CISA KEV
Not listed
Weakness
CWE-22, CWE-73
Affected
basercms/basercms
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.