What is CVE-2021-39125?

CVE-2021-39125 is a medium-severity vulnerability in Atlassian Data Center. CVSS score: 5.3/10. Published 2021-09-14.

How severe is CVE-2021-39125?

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

Vulnerability in Atlassian Data Center

CVE-2021-39125

Affected versions of Atlassian Jira Server and Data Center allow anonymous remote attackers to discover the usernames of users via an enumeration vulnerability in the password reset page. The affected versions are before version 8.5.10, and from version 8.6.0 before 8.13.1.

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: 0.019 (79.7th percentile), scored 2026-11-01.

Low probability of exploitation in the next 30 days, but still tracked. 80th percentile — 79.7% 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: 0.019 · change: +0.005

Affected products

Atlassian Data Center
Atlassian Jira
Atlassian Jira Data Center — versions unspecified, 8.6.0
Atlassian Jira Server — versions unspecified, 8.6.0
Atlassian Jira Server

References

jira.atlassian.com/browse/JRASERVER-72009 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-39125?: CVE-2021-39125 is a medium-severity vulnerability in Atlassian Data Center. CVSS score: 5.3/10. Published 2021-09-14.
How severe is CVE-2021-39125?: Medium severity. CVSS v3 base score is 5.3 out of 10.