CVE-2026-56662
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.25%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 9.6 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
- EPSS
- 0.25% probability · 16th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-352
- Source
- security-advisories@github.com
EPSS moved from 0.2% on 2 October 2026 to 0.2% on 26 October 2026.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.