Is CVE-2021-47855 in the CISA KEV catalog?

No. CVE-2021-47855 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-47855?

CVE-2021-47855 has a CVSS v3 base score of 7.2 (HIGH).

What is the EPSS score for CVE-2021-47855?

CVE-2021-47855 has an EPSS score of 0.24% (15th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2021-47855

HIGH

7.2

CVSS v3

NVD

Description

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.

CWE-79Cross-Site Scripting (XSS)

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeChanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Exploit Intelligence

0.24%probability of exploitation in 30 days

15thpercentile

Low risk: more likely to be exploited than 15% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-01-26.