What is CVE-2020-8789?

CVE-2020-8789 is a medium-severity vulnerability in Composr Project, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2020-05-22.

How severe is CVE-2020-8789?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Composr Project

CVE-2020-8789

Composr 10.0.30 allows Persistent XSS via a Usergroup name under the Security configuration.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2020-05-22 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (49.4th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Composr Project

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

packetstormsecurity.com/files/157787/Composr-CMS-10.0.30-Cross-Site-Scripting.h… (Exploit, VDB Entry, Third Party Advisory)
seclists.org/fulldisclosure/2020/May/39 (mailing-list, Exploit, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2020-8789?: CVE-2020-8789 is a medium-severity vulnerability in Composr Project, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2020-05-22.
How severe is CVE-2020-8789?: Medium severity. CVSS v3 base score is 5.4 out of 10.