Full Report
Atlassian security advisory (AV26-1002)
Analysis Summary
# Vulnerability: Arbitrary File Access in Multiple Atlassian Products
## CVE Details
- **CVE ID:** CVE-2026-21589
- **CVSS Score:** Not explicitly listed in the advisory text, but typically rated as **High** to **Critical** for arbitrary file access.
- **CWE:** CWE-22 (Improper Limitation of a Pathname to a Restricted Directory / Path Traversal)
## Affected Systems
- **Products:**
- Bamboo (Data Center & Server)
- Bitbucket (Data Center & Server)
- Confluence (Data Center & Server)
- Crowd (Data Center & Server)
- Crucible (Data Center & Server)
- Fisheye (Data Center & Server)
- Jira Service Management (Data Center & Server)
- Jira Software (Data Center & Server)
- **Versions:**
- **Bamboo Data Center:** 10.2.4 and prior; 12.1.12 and prior
- **Bamboo Server:** All versions
- **Bitbucket Data Center:** 10.2.8 and prior; 10.5.1 and prior; 9.4.26 and prior
- **Bitbucket Server:** All versions
- **Confluence Data Center:** 10.2.19 and prior; 9.2.26 and prior
- **Confluence Server:** All versions
- **Crowd Data Center:** 6.3.7, 7.0.3, 7.1.1, 7.2.4 and prior
- **Crowd Server:** All versions
- **Crucible/Fisheye:** 4.9.15 and prior
- **Jira Service Management:** 10.3.26, 11.3.12, 5.12.40 and prior
- **Jira Software:** 10.3.26, 11.3.12, 9.12.40 and prior
- **Configurations:** Default installations of the listed versions are susceptible.
## Vulnerability Description
CVE-2026-21589 is an **Arbitrary File Access** vulnerability. It allows an attacker to bypass directory restrictions and access sensitive files on the server's filesystem that should not be reachable via the web application. This is typically achieved through path traversal techniques, potentially leading to the exposure of configuration files, credentials, or system data.
## Exploitation
- **Status:** Not explicitly stated as exploited in the wild; however, the advisory indicates high priority for patching.
- **Complexity:** Low (Path traversal vulnerabilities generally require minimal specialized knowledge to exploit).
- **Attack Vector:** Network (Remote)
## Impact
- **Confidentiality:** High (Access to sensitive configuration files and system data).
- **Integrity:** Medium (Potential for file manipulation depending on system permissions).
- **Availability:** Low (Primary impact is data exposure).
## Remediation
### Patches
Atlassian recommends upgrading to the following versions (or later):
- **Bamboo Data Center:** Upgrade to 10.2.5 or 12.1.13
- **Bitbucket Data Center:** Upgrade to 10.2.9, 10.5.2, or 9.4.27
- **Confluence Data Center:** Upgrade to 10.2.20 or 9.2.27
- **Crowd Data Center:** Upgrade to 6.3.8, 7.0.4, 7.1.2, or 7.2.5
- **Crucible/Fisheye:** Upgrade to versions newer than 4.9.15
- **Jira Service Management:** Upgrade to 10.3.27, 11.3.13, or 5.12.41
- **Jira Software:** Upgrade to 10.3.27, 11.3.13, or 9.12.41
*Note: For "Server" editions, users are advised to migrate to supported Data Center versions or apply the latest available maintenance release as these products have reached/are reaching end-of-life.*
### Workarounds
No specific functional workarounds were provided in the bulletin. Immediate patching is the recommended course of action.
## Detection
- **Indicators of Compromise:** Look for unusual URL patterns in web server logs containing `../`, `..%2f`, or `..%5c` sequences targeting Atlassian application directories.
- **Detection methods and tools:** Audit file access logs for the service account running the Atlassian suite to identify access to non-application files (e.g., `/etc/passwd`, `.env`, or config files).
## References
- Atlassian Advisory: hxxps[://]confluence[.]atlassian[.]com/security/cve-2026-21589-arbitrary-file-access-vulnerability-impacts-multiple-products-1870495748[.]html
- General Bulletins: hxxps[://]confluence[.]atlassian[.]com/security/security-advisories-bulletins-1236937381[.]html
- Cyber Centre Alert: hxxps[://]www[.]cyber[.]gc[.]ca/en/alerts-advisories/atlassian-security-advisory-av26-1002