How severe is CVE-2020-4021?

CVE-2020-4021 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-4021 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-4021?

CVE-2020-4021 primarily affects Atlassian Jira. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-4021?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-4021 published?

CVE-2020-4021 was published on 2020-06-01 and last updated on 2026-06-17.

CVE-2020-4021

CVE-2020-4021 is a medium-severity vulnerability in Atlassian Jira with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 1% (59th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Atlassian Jira
Published: 2020-06-01
Last modified: 2026-06-17

Description

Affected versions are: Before 8.5.5, and from 8.6.0 before 8.8.1 of Atlassian Jira Server and Data Center allow remote attackers to inject arbitrary HTML or JavaScript via a cross site scripting (XSS) vulnerability in the XML export view.

Frequently asked questions

What is CVE-2020-4021?: Affected versions are: Before 8.5.5, and from 8.6.0 before 8.8.1 of Atlassian Jira Server and Data Center allow remote attackers to inject arbitrary HTML or JavaScript via a cross site scripting (XSS) vulnerability in the XML export view.
How severe is CVE-2020-4021?: CVE-2020-4021 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-4021 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-4021?: CVE-2020-4021 primarily affects Atlassian Jira. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-4021?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-4021 published?: CVE-2020-4021 was published on 2020-06-01 and last updated on 2026-06-17.

References

https://jira.atlassian.com/browse/JRASERVER-70923

Affected products (4)

cpe:2.3:a:atlassian:jira:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:jira_data_center:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:jira_server:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:jira_software_data_center:*:*:*:*:*:*:*:*

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