Atlassian Data Center Arbitrary File Access Vulnerability Advisory (CVE-2026-21589)
Executive & SecOps Summary
SECOPS ASSESSMENTWide range of Atlassian Data Center products including Bitbucket, Confluence, Jira, Bamboo, and Crowd.
Unauthenticated remote attackers can access sensitive files within the web application root directory, leading to information disclosure.
Immediately upgrade to the fixed versions provided by Atlassian and restrict access to sensitive web root files.
Affected Products & Version Scope
Remediation & Live Workaround Commands
PATCH & WORKAROUNDThe primary remediation is to upgrade to a fixed version immediately.
1. Recommended Fix Versions
- Bitbucket: 9.4.26, 10.2.8, 10.5.1+
- Confluence: 9.2.26, 10.2.19+
- Jira Software: 9.12.40, 10.3.26, 11.3.12+
- Jira Service Management: 5.12.40, 10.3.26, 11.3.12+
- Bamboo: 10.2.24, 12.1.12+
- Crowd: 6.3.7, 7.0.3, 7.1.7, 7.2.4+
- Crucible/Fisheye: 4.9.15+
2. Temporary Mitigation (WAF/Proxy)
If immediate patching is not possible, implement WAF rules to block access to sensitive file extensions in the web root.
# Example: Block access to sensitive files via Nginx
location ~* \.(xml|conf|properties|log)$ {
deny all;
return 403;
}Block Exploits Instantly with Managed Virtual Patching Rules
Can't patch production immediately? Deploy managed WAF rules at the edge to intercept RCE, SQLi, and deserialization payloads before they hit your origin server.
Technical Root Cause & Exploitation Mechanics
CVE-2026-21589 is an Arbitrary File Access vulnerability (CWE-552) resulting from improper access controls in the web root directory of Atlassian Data Center products. While the vulnerability does not permit directory enumeration, an attacker with prior knowledge of specific file paths can bypass authentication to retrieve sensitive data. This vulnerability is currently listed in the CISA KEV catalog and maintains an EPSS score of 0.94, indicating a very high probability of active exploitation. Exposure of configuration files or system metadata could facilitate further lateral movement or full system compromise.
Official Vendor Advisories & References
This is a vulnerability in Bitbucket Data Center, Confluence Data Center, Jira Service Management Data Center, Jira Software Data Center, Bamboo Data Center. Crowd Data Center, Crucible and Fisheye. This Arbitrary File Access vulnerability allows an unauthenticated attacker to access specific files within the web application root directory in affected versions. Exploitation requires prior knowledge of the target file's exact name and path; this vulnerability does not allow attackers to enumerate or list directory contents. In some configurations, there may be some sensitive files that make this highly severe. This vulnerability allows an unauthenticated remote attacker to access specific files within the web application root directory in affected versions. The vulnerability must be addressed for affected versions of: -- Bitbucket Data Center, introduced in version >= 4.6.0, fix versions: 9.4.26, 10.2.8, 10.5.1 -- Confluence Data Center, introduced in version >= 5.10.0, fix versions 9.2.26, 10.2.19 -- Crowd Data Center, introduced in version >= 2.11.0, fix versions 6.3.7, 7.0.3, 7.1.7, 7.2.4 -- Jira Software Data Center, introduced in version >= 7.1.0, fix versions 9.12.40, 10.3.26, 11.3.12 -- Jira Service Management Data Center, introduced in version >= 3.1.0, fix versions 5.12.40, 10.3.26, 11.3.12 -- Bamboo Data Center >= 7.0.1, fix versions 10.2.24, 12.1.12 -- Crucible, fix versions 4.9.15 -- Fisheye, fix version 4.9.15 -- Exploitation requires prior knowledge of the target file's exact name and path. The vulnerability does not include the capability to enumerate or list directory contents.
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