What is CVE-2021-47855?

CVE-2021-47855 is a high-severity vulnerability in Litespeed Technologies Openlitespeed, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-01-21.

How severe is CVE-2021-47855?

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

XSS in Litespeed Technologies Openlitespeed

CVE-2021-47855

Openlitespeed 1.7.9 contains a stored cross-site scripting vulnerability in the dashboard's Notes parameter that allows administrators to inject malicious scripts. Attackers can craft a payload in the Notes field during listener configuration that will execute when an administrator clicks on the Default Icon.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (15.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

Affected products

Litespeed Technologies Openlitespeed — versions 1.7.9

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

disclosure@vulncheck.com (exploit)
disclosure@vulncheck.com (product)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2021-47855?: CVE-2021-47855 is a high-severity vulnerability in Litespeed Technologies Openlitespeed, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-01-21.
How severe is CVE-2021-47855?: High severity. CVSS v3 base score is 7.2 out of 10.