CVE-2026-54611
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.
Does this matter?
Lower severity and a low EPSS score (0.66%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H
- EPSS
- 0.66% probability · 51th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-94, CWE-434
- Source
- security-advisories@github.com
EPSS 0.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.