CVE-2026-21861

CRITICAL 9.1

baserCMS: OS Command Injection Leading to Remote Code Execution (RCE)

CVSS Score

9.1

EPSS Score

0.2%

EPSS Percentile

39th

baserCMS is a website development framework. Prior to version 5.2.3, baserCMS contains an OS command injection vulnerability in the core update functionality. An authenticated administrator can execute arbitrary OS commands on the server due to improper handling of user-controlled input that is directly passed to exec() without sufficient validation or escaping. This issue has been patched in version 5.2.3.

CWE	CWE-78
Vendor	baserproject
Product	basercms
Published	Mar 31, 2026
Last Updated	Mar 31, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

baserproject / basercms

< 5.2.3

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/baserproject/basercms/security/advisories/GHSA-qxmc-6f24-g86g basercms.net: https://basercms.net/security/JVN_20837860 github.com: https://github.com/baserproject/basercms/releases/tag/5.2.3