Path Traversal in Basercms
CVE-2026-30940
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.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.011 (63.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 63.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.010 · newest: 0.011 · change: +0.000
Affected products
- Basercms
- Baserproject Basercms — versions < 5.2.3
Weakness classification (CWE)
References
- github.com/baserproject/basercms/security/advisories/GHSA-c5c6-37vq-pjcq (Exploit, Vendor Advisory)
- basercms.net/security/JVN_20837860 (Vendor Advisory)
- github.com/baserproject/basercms/releases/tag/5.2.3 (Release Notes)
Frequently asked questions
- What is CVE-2026-30940?
- CVE-2026-30940 is a high-severity vulnerability in Basercms, classified under Path Traversal. CVSS score: 7.2/10. Published 2026-03-31.
- How severe is CVE-2026-30940?
- High severity. CVSS v3 base score is 7.2 out of 10.