CVE-2026-54611

medium

Assigned by CNA: github_m

Published 2026-09-08 · Modified 2026-09-08

Discuss on Community Propose mitigation

CVSS v3

5.5

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

CVSS v4 NEW

—

not yet in upstream

VIR risk

5.5

Description

InstantCMS is a free and open source content management system. Versions prior to 2.18.2 have a Remote Code Execution (RCE) issue that allows remote authenticated attackers to execute any PHP code via the component installer. It is possible to upload a malicious component into the server, however, it won't be installed, but upload files will be executed. Normally all php files in upload folder are not executed, however, by uploading custom .htaccess it becomes possible. Version 2.18.2 contains a fix.

Predictions

Exploit likelihood

65%

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

CWEs

CWE-94 CWE-434

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

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