What is CVE-2018-16821?

CVE-2018-16821 is a medium-severity vulnerability in Seacms, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 5.3/10. Published 2018-09-21.

How severe is CVE-2018-16821?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Arbitrary file upload in Seacms

CVE-2018-16821

SeaCMS 6.64 allows arbitrary directory listing via upload/admin/admin_template.php?path=../templets/../../ requests.

Vulnerability class: Unrestricted File Upload

Published 2018-09-21 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.010 (61.7th percentile), scored 2026-10-03.

Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 61.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

Seacms — versions 6.64

Weakness classification (CWE)

CWE-434 — Unrestricted Upload of File with Dangerous Type

References

blog.51cto.com/13770310/2177212 (Exploit, Third Party Advisory)
www.seacms.net/thread-6249-1-1.html (Vendor Advisory)

Frequently asked questions

What is CVE-2018-16821?: CVE-2018-16821 is a medium-severity vulnerability in Seacms, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 5.3/10. Published 2018-09-21.
How severe is CVE-2018-16821?: Medium severity. CVSS v3 base score is 5.3 out of 10.