CVE-2021-26081: Atlassian Data Center

Medium severity, CVSS 5.3. EPSS: 1.2% chance of exploitation in the next 30 days.

REST API in Atlassian Jira Server and Jira Data Center before version 8.5.14, from version 8.6.0 before 8.13.6, and from version 8.14.0 before 8.16.1 allows remote attackers to enumerate usernames via a Sensitive Data Exposure vulnerability in the `/rest/api/latest/user/avatar/temporary` endpoint.

Affected products

• Atlassian Data Center: before 8.5.14 (fixed in 8.5.14)
• Atlassian Jira: before 8.5.14 (fixed in 8.5.14)
• Atlassian Jira Data Center: from 8.6.0, before 8.13.6 (fixed in 8.13.6); from 8.14.0, before 8.16.1 (fixed in 8.16.1)
• Atlassian Jira Server: from 8.6.0, before 8.13.6 (fixed in 8.13.6); from 8.14.0, before 8.16.1 (fixed in 8.16.1)

Published 2021-07-20. Last modified 2026-06-17.