What is CVE-2020-8439?

CVE-2020-8439 is a medium-severity vulnerability in Monstra, classified under Direct Request (Forced Browsing). CVSS score: 6.5/10. Published 2020-03-07.

How severe is CVE-2020-8439?

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

Vulnerability in Monstra

CVE-2020-8439

Monstra CMS through 3.0.4 allows remote authenticated users to take over arbitrary user accounts via a modified login parameter to an edit URI, as demonstrated by login=victim to the users/21/edit URI.

Published 2020-03-07 · 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:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.016 (74.7th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 74.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000

Affected products

Monstra

Weakness classification (CWE)

CWE-425 — Direct Request (Forced Browsing)

References

uploadboy.me/cn40ne6p89t6/POC.mp4.html (Exploit, Third Party Advisory)
cert.ikiu.ac.ir/public-files/pages/attachments/11/02630f153869936d555a79f89d717… (Third Party Advisory, Mitigation)

Frequently asked questions

What is CVE-2020-8439?: CVE-2020-8439 is a medium-severity vulnerability in Monstra, classified under Direct Request (Forced Browsing). CVSS score: 6.5/10. Published 2020-03-07.
How severe is CVE-2020-8439?: Medium severity. CVSS v3 base score is 6.5 out of 10.