What is CVE-2018-19201?

CVE-2018-19201 is a medium-severity vulnerability in Mybb, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2019-03-29.

How severe is CVE-2018-19201?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Mybb

CVE-2018-19201

A reflected XSS vulnerability in the ModCP Profile Editor in MyBB before 1.8.20 allows remote attackers to inject JavaScript via the 'username' parameter.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2019-03-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (54.4th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 54.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Mybb

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

blog.mybb.com/2019/02/27/mybb-1-8-20-released-security-maintenance-release/ (Release Notes, Vendor Advisory)
github.com/mybb/mybb/blob/feature/SECURITY.md (Third Party Advisory)

Frequently asked questions

What is CVE-2018-19201?: CVE-2018-19201 is a medium-severity vulnerability in Mybb, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2019-03-29.
How severe is CVE-2018-19201?: Medium severity. CVSS v3 base score is 6.1 out of 10.