Critical severity · published Oct 1, 2026
CVE-2026-56662
GetSimple CMS: Missing CSRF protection in UpdateCE allows forging a privileged server-side update request
9.6
CVSS
0.2%
EPSS
No
On KEV
Description
GetSimple CMS is a content management system (CMS), and GetSimple CMS CE is the community edition of that CMS. Prior to version 1.5, the UpdateCE update form contained no anti-CSRF token, and the POST handler performed no token or request-origin verification. A remote attacker can host a page that auto-submits a forged POST to the update endpoint; when an authenticated administrator visits it, the server performs an attacker-directed download-and-deploy operation in the administrator's session — with no further interaction. Because the deployed content is executed (see the related ZIP-extraction advisory), this yields remote code execution. The url field is additionally written into the form unescaped, providing a secondary HTML-injection sink via a malicious upgrade.json. This issue has been patched in version 1.5.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 16% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GE
GetSimpleCMS-CE · GetSimpleCMS-CE
< 1.5 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-56662
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-56662
x_refsource_CONFIRM
https://github.com/GetSimpleCMS-CE/GetSimpleCMS-CE/security/advisories/GHSA-2rxv-4g4m-573w
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