CVE-2026-56661

high

Assigned by CNA: github_m

Published 2026-10-01 · Modified 2026-10-01

Discuss on Community Propose mitigation

CVSS v3

7.5

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:L

CVSS v4 NEW

—

not yet in upstream

VIR risk

7.5

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.

Predictions

Exploit likelihood

83%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

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

CWEs

CWE-918

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.