What is CVE-2021-39117?

CVE-2021-39117 is a medium-severity vulnerability in Atlassian Data Center, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2021-08-30.

How severe is CVE-2021-39117?

Medium severity. CVSS v3 base score is 4.8 out of 10.

Is CVE-2021-39117 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Atlassian Data Center

CVE-2021-39117

The AssociateFieldToScreens page in Atlassian Jira Server and Data Center before version 8.18.0 allows remote attackers to inject arbitrary HTML or JavaScript via a Cross-Site Scripting (XSS) vulnerability via the name of a custom field.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-08-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.006 (48.4th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 48.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Atlassian Data Center
Atlassian Jira
Atlassian Jira Data Center — versions unspecified
Atlassian Jira Server — versions unspecified

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

References

jira.atlassian.com/browse/JRASERVER-72597 (Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2021-39117?: CVE-2021-39117 is a medium-severity vulnerability in Atlassian Data Center, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2021-08-30.
How severe is CVE-2021-39117?: Medium severity. CVSS v3 base score is 4.8 out of 10.
Is CVE-2021-39117 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.