High 7.2Published Mar 30, 2026

CVE-2026-30940baserCMS: Path Traversal in Theme File API Leads to Arbitrary File Write and RCE

Updated under an hour ago (Oct 27, 2026, 12:10 AM ET)

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It affects baserproject basercms and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for baserproject basercms

Exploited in the last 30 days

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: 7.2 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-22, CWE-73
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Apr 2, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

baserproject basercms baserproject:basercms (from the name)	before 5.2.3	CNA record
basercms basercms basercms:basercms	before 5.2.3	NVD

References

References

https://github.com/baserproject/basercms/security/advisories/GHSA-c5c6-37vq-pjcq	x-refsource-confirm, exploit, vendor-advisory
https://basercms.net/security/JVN_20837860	x-refsource-misc, vendor-advisory
https://github.com/baserproject/basercms/releases/tag/5.2.3	x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.