Is CVE-2021-47839 in the CISA KEV catalog?

No. CVE-2021-47839 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-47839?

CVE-2021-47839 has a CVSS v3 base score of 7.2 (HIGH).

What is the EPSS score for CVE-2021-47839?

CVE-2021-47839 has an EPSS score of 0.41% (32th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2021-47839

HIGH

7.2

CVSS v3

NVD

Description

Marky 0.0.1 contains a persistent cross-site scripting vulnerability that allows attackers to inject malicious scripts into markdown files. Attackers can upload crafted markdown files with embedded JavaScript payloads that execute when the file is opened, potentially enabling remote code execution.

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

0.41%probability of exploitation in 30 days

32ndpercentile

Low risk: more likely to be exploited than 32% 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.