What’s Vulnerable › Vulnerabilities

CVE-2026-56661: GetSimple CMS: Server-Side Request Forgery in the UpdateCE update endpoint

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-01 · updated 2026-10-01
• Weakness: CWE-918

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 update handler fetches a user-supplied URL with file_get_contents() after only format validation (FILTER_VALIDATE_URL) — there is no validation of the request destination. An attacker who can submit the form can make the server issue requests to arbitrary destinations, including internal-only services and cloud metadata endpoints (169.254.169.254). The fetched response body is written to a web-accessible file (/Tmpfile.zip) and is not deleted when the content is not a valid ZIP, turning this into a full-read SSRF: the attacker can retrieve the response of the internal request directly. This issue has been patched in version 1.5.

Affected products

• GetSimpleCMS-CE: before 1.5

References

• https://github.com/GetSimpleCMS-CE/GetSimpleCMS-CE/security/advisories/GHSA-r7v8-mx29-5q8h
• https://github.com/GetSimpleCMS-CE/GetSimpleCMS-CE/security/advisories/GHSA-r7v8-mx29-5q8h

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