IRONSMITHINTEL
MEDIUMCVSS5.3
|
Actively Exploited
|CISA KEV|CVE-2021-26086|Auth: none — unauthenticated|Reboot: required|Manual only

Atlassian Jira Server and Data Center Path Traversal Vulnerability

Atlassian Jira Server and Data Center contain a path traversal vulnerability that allows a remote attacker to read particular files in the /WEB-INF/web.xml endpoint.

Published Aug 16, 2021 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve partial data exposure. Federal agencies are required to remediate by 2024-12-03 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Path Traversal (CWE-22) vulnerability in Atlassian Jira Server and Data Center. 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. Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.

📧

Phishing link

🖼

Malicious file

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Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

IT Security
Running jira data center: v < 8.5.14, 8.6.0 ≤ v < 8.13.6, 8.14.0 ≤ v < 8.16.1; jira server: v < 8.5.14, 8.6.0 ≤ v < 8.13.6, 8.14.0 ≤ v < 8.16.1
Real-world incidentsWhat we've seen

Active exploitation documented in the wild. Threat-research write-up: http://packetstormsecurity.com/files/164405/Atlassian-Jira-Server-Data-Center-8.4.0-File-Read.html

How to patch

Manual remediation steps

Apply the Vendor Patch

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.

CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

References

    1
    Vendor advisory: https://jira.atlassian.com/browse/JRASERVER-72695
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2021-26086
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26086
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