Arbitrary file upload in Phpkf Cms

CVE-2021-47753

phpKF CMS 3.00 Beta y6 contains an unauthenticated file upload vulnerability that allows remote attackers to execute arbitrary code by bypassing file extension checks. Attackers can upload a PHP file disguised as a PNG, rename it, and execute system commands through a crafted web shell parameter.

Vulnerability class: Unrestricted File Upload

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (53.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 53.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-47753: held from 0.007 to 0.008.

EPSS over last 30 days · oldest: 0.007 · newest: 0.008 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-47753?
CVE-2021-47753 is a critical-severity vulnerability in Phpkf Cms, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2026-01-15.
How severe is CVE-2021-47753?
Critical severity. CVSS v3 base score is 9.8 out of 10.