How severe is CVE-2018-20239?

CVE-2018-20239 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-2018-20239 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-20239?

CVE-2018-20239 primarily affects Atlassian Application Links. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-20239?

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

When was CVE-2018-20239 published?

CVE-2018-20239 was published on 2019-04-30 and last updated on 2026-06-17.

CVE-2018-20239

CVE-2018-20239 is a medium-severity vulnerability in Atlassian Application Links 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: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Atlassian Application Links
Published: 2019-04-30
Last modified: 2026-06-17

Description

Application Links before version 5.0.11, from version 5.1.0 before 5.2.10, from version 5.3.0 before 5.3.6, from version 5.4.0 before 5.4.12, and from version 6.0.0 before 6.0.4 allows remote attackers to inject arbitrary HTML or JavaScript via a cross site scripting (XSS) vulnerability in the applinkStartingUrl parameter. The product is used as a plugin in various Atlassian products where the following are affected: Confluence before version 6.15.2, Crucible before version 4.7.0, Crowd before version 3.4.3, Fisheye before version 4.7.0, Jira before version 7.13.3 and 8.x before 8.1.0.

Frequently asked questions

What is CVE-2018-20239?: Application Links before version 5.0.11, from version 5.1.0 before 5.2.10, from version 5.3.0 before 5.3.6, from version 5.4.0 before 5.4.12, and from version 6.0.0 before 6.0.4 allows remote attackers to inject arbitrary HTML or JavaScript via a cross site scripting (XSS) vulnerability in the applinkStartingUrl parameter. The product is used as a plugin in various Atlassian products where the following are affected: Confluence before version 6.15.2, Crucible before version 4.7.0, Crowd before version 3.4.3, Fisheye before version 4.7.0, Jira before version 7.13.3 and 8.x before 8.1.0.
How severe is CVE-2018-20239?: CVE-2018-20239 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-2018-20239 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-20239?: CVE-2018-20239 primarily affects Atlassian Application Links. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-20239?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-20239 published?: CVE-2018-20239 was published on 2019-04-30 and last updated on 2026-06-17.

References

Affected products (8)

cpe:2.3:a:atlassian:application_links:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:confluence_data_center:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:confluence_server:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:crowd:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:crucible:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:fisheye:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:jira_data_center:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:jira_server:*:*:*:*:*:*:*:*

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