Auth bypass in Getsimplecms

CVE-2026-53952

GetSimple CMS is a content management system (CMS), and GetSimple CMS CE is the community edition of that CMS. A logic flaw in GetSimple CMS (v3.4.0a and below) and GetSimpleCMS-CE (v3.3.22 and below) allows unauthenticated attackers to create a new administrator account. The application features an automated security control designed to delete the sensitive `admin/setup.php` file post-installation. However, this control is neutralized by a self-exclusion bug within the deletion logic, leaving the setup script accessible for unauthorized account creation even after a legitimate installation is completed. As of time of publication, no known patched versions are available.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (46.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-53952: held from 0.006 to 0.006.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-53952?
CVE-2026-53952 is a critical-severity vulnerability in Getsimplecms, classified under Improper Authorization. CVSS score: 9.8/10. Published 2026-09-11.
How severe is CVE-2026-53952?
Critical severity. CVSS v3 base score is 9.8 out of 10.