What is CVE-2018-20911?

CVE-2018-20911 is a high-severity vulnerability in Cpanel, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2019-08-01.

How severe is CVE-2018-20911?

High severity. CVSS v3 base score is 7.2 out of 10.

XSS in Cpanel

CVE-2018-20911

cPanel before 70.0.23 allows code execution because "." is in @INC during a Perl syntax check of cpaddonsup (SEC-359).

Vulnerability class: XSS (Cross-Site Scripting)

Published 2019-08-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.016 (74.6th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 74.6% 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

Cpanel

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

documentation.cpanel.net/display/CL/70+Change+Log (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2018-20911?: CVE-2018-20911 is a high-severity vulnerability in Cpanel, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2019-08-01.
How severe is CVE-2018-20911?: High severity. CVSS v3 base score is 7.2 out of 10.