CVE-2026-30879 is a CWE-79 cross-site scripting vulnerability affecting baserCMS, a website development framework. The issue arises from improper neutralization of input in blog posts, allowing potential injection of malicious scripts. This vulnerability affects all baserCMS versions prior to 5.2.3. The vendor released version 5.2.3 which includes a patch that fixes this issue. The vulnerability has a CVSS 4.0 score of 6.9, reflecting a medium severity with network attack vector, low complexity, no privileges required, and no user interaction needed.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary scripts in the context of the affected website, potentially leading to session hijacking, defacement, or other malicious actions. However, no known exploits have been reported in the wild. The impact is limited to affected baserCMS installations running versions earlier than 5.2.3.

Upgrade baserCMS to version 5.2.3 or later, where this cross-site scripting vulnerability has been patched. No other mitigation steps are indicated by the vendor advisory.