What is CVE-2021-39118?

CVE-2021-39118 is a medium-severity vulnerability in Atlassian Data Center. CVSS score: 5.3/10. Published 2021-09-14.

How severe is CVE-2021-39118?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Is CVE-2021-39118 known to be exploited?

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

Vulnerability in Atlassian Data Center

CVE-2021-39118

Affected versions of Atlassian Jira Server and Data Center allow remote attackers to discover the usernames and full names of users via an enumeration vulnerability in the /rest/api/1.0/render endpoint. The affected versions are before version 8.19.0.

Published 2021-09-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.014 (72.9th percentile), scored 2026-11-01.

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 72.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: 0.000

Affected products

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

Public proof-of-concept exploits

References

jira.atlassian.com/browse/JRASERVER-72736 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-39118?: CVE-2021-39118 is a medium-severity vulnerability in Atlassian Data Center. CVSS score: 5.3/10. Published 2021-09-14.
How severe is CVE-2021-39118?: Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2021-39118 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.