Limited Remote File Read in Jira Software Server - CVE-2021-26086

Affected versions of Atlassian Jira Server and Data Center allow remote attackers to read particular files via a path traversal vulnerability in the /WEB-INF/web.xml endpoint.

The affected versions are before version 8.5.14, from version 8.6.0 before 8.13.6, and from version 8.14.0 before 8.16.1.

Affected versions:

• version < 8.5.14
• 8.6.0 ≤ version < 8.13.6
• 8.14.0 ≤ version < 8.16.1

Fixed versions:

• 8.5.14
• 8.13.6
• 8.16.1
• 8.17.0  

Mitigation

Until the upgrade you may use the following workaround to protect the files:
https://confluence.atlassian.com/jirakb/workaround-for-cve-2019-15004-979416164.html

Note: Workaround 1 in the above KB article is not valid for this purpose. Workaround 2 (proxy/load balancer configuration) is valid.