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.
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 · 64th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-22, CWE-73
- Affected
- basercms/basercms
- Source
- security-advisories@github.com
EPSS 1.0% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://basercms.net/security/JVN_20837860Vendor Advisory
- https://github.com/baserproject/basercms/releases/tag/5.2.3Release Notes
- https://github.com/baserproject/basercms/security/advisories/GHSA-c5c6-37vq-pjcqExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.