What is CVE-2020-4028?

CVE-2020-4028 is a medium-severity vulnerability in Atlassian Jira, classified under Observable Discrepancy. CVSS score: 5.3/10. Published 2020-06-23.

How severe is CVE-2020-4028?

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

Vulnerability in Atlassian Jira

CVE-2020-4028

Versions before 8.9.1, Various resources in Jira responded with a 404 instead of redirecting unauthenticated users to the login page, in some situations this may have allowed unauthorised attackers to determine if certain resources exist or not through an Information Disclosure vulnerability.

Published 2020-06-23 · 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: 0.009 (57.9th percentile), scored 2026-10-20.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 57.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

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

Weakness classification (CWE)

CWE-203 — Observable Discrepancy

References

jira.atlassian.com/browse/JRASERVER-71175 (Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2020-4028?: CVE-2020-4028 is a medium-severity vulnerability in Atlassian Jira, classified under Observable Discrepancy. CVSS score: 5.3/10. Published 2020-06-23.
How severe is CVE-2020-4028?: Medium severity. CVSS v3 base score is 5.3 out of 10.