What is CVE-2021-3256?

CVE-2021-3256 is a medium-severity vulnerability in Kuaifan Kuaifancms, classified under Argument Injection. CVSS score: 6.5/10. Published 2021-06-11.

How severe is CVE-2021-3256?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Kuaifan Kuaifancms

CVE-2021-3256

KuaiFanCMS V5.x contains an arbitrary file read vulnerability in the html_url parameter of the chakanhtml.module.php file.

Published 2021-06-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.009 (57.8th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 57.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Kuaifan Kuaifancms — versions 5.0

Weakness classification (CWE)

CWE-88 — Argument Injection

References

github.com/poropro/kuaifan/issues/3 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2021-3256?: CVE-2021-3256 is a medium-severity vulnerability in Kuaifan Kuaifancms, classified under Argument Injection. CVSS score: 6.5/10. Published 2021-06-11.
How severe is CVE-2021-3256?: Medium severity. CVSS v3 base score is 6.5 out of 10.