CVE-2021-43942: Atlassian Jira Server

Medium severity, CVSS 6.1. EPSS: 55.4% chance of exploitation in the next 30 days.

Affected versions of Atlassian Jira Server and Data Center allow remote attackers to inject arbitrary HTML or JavaScript via a Reflected Cross-Site Scripting (XSS) vulnerability in the /rest/collectors/1.0/template/custom endpoint. To exploit this issue, the attacker must trick a user into visiting a malicious website. The affected versions are before version 8.13.15, and from version 8.14.0 before 8.20.3.

Affected products

• Atlassian Jira Server: from 8.14.0, before 8.20.3 (fixed in 8.20.3)
• Atlassian Jira Server And Data Center: before 8.13.5 (fixed in 8.13.5)

Published 2022-01-04. Last modified 2026-06-17.