RCE in Cmsimple

CVE-2021-47735

CMSimple 5.4 contains an authenticated remote code execution vulnerability that allows logged-in attackers to inject malicious PHP code into template files. Attackers can exploit the template editing functionality by crafting a reverse shell payload and saving it through the template editing endpoint with a valid CSRF token.

Vulnerability class: RCE (Remote Code Execution)

EPSS: 0.008 (52.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-47735?
CVE-2021-47735 is a high-severity vulnerability in Cmsimple, classified under Code Injection. CVSS score: 8.8/10. Published 2025-12-23.
How severe is CVE-2021-47735?
High severity. CVSS v3 base score is 8.8 out of 10.