# CVE-2026-21589: Atlassian Data Center arbitrary file access without authentication

Source: https://junglewise.ai/threats/cve-2026-21589-h3-summary-this-is-a-vulnerability-in-bitbucket-data-center  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-05. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-21589 · Severity: critical · Exploited in the wild · Published 2026-10-05

Multiple Atlassian Data Center products—Bitbucket, Confluence, Jira, Bamboo, Crowd, Crucible, and Fisheye—allow unauthenticated attackers to read files from the application's web root if they know the exact file path. An attacker with knowledge of sensitive file locations (such as configuration files or database backups) could retrieve them without logging in, potentially exposing credentials, API keys, or other secrets stored in the web directory.

Technologies: [Atlassian Confluence Data Center](https://junglewise.ai/threats/technologies/confluence-data-center). Vendors: [Atlassian](https://junglewise.ai/threats/vendors/atlassian).

## Quick answers

**Is CVE-2026-21589 exploited in the wild?** Yes. CVE-2026-21589 is known to be exploited in the wild, first recorded on 15 October 2026. Treat it as urgent.

**How severe is CVE-2026-21589?** Critical severity, published 5 October 2026.

**Which products and versions are affected?** Atlassian Bamboo Data Center 7.0.1 and later; Atlassian Bitbucket Data Center 4.6.0 and later; Atlassian Confluence Data Center 5.10.0 and later; Atlassian Crowd Data Center 2.11.0 and later; and 4 more.

**Is there a fix for CVE-2026-21589?** Yes: fixed in Bitbucket Data Center 9.4.26, 10.2.8, 10.5.1; Confluence Data Center 9.2.26, 10.2.19; Crowd Data Center 6.3.7, 7.0.3, 7.1.1, 7.2.4; Jira Software Data Center 9.12.40, 10.3.26, 11.3.12; Jira Service Management Data Center 5.12.40, 10.3.26, 11.3.12; Bamboo Data Center 10.2.24, 12.1.12; Crucible 4.9.15; Fisheye 4.9.15. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-21589 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-21589?** Check whether you run Atlassian Bamboo Data Center, Atlassian Bitbucket Data Center, Atlassian Confluence Data Center or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Bitbucket Data Center 9.4.26, 10.2.8, 10.5.1; Confluence Data Center 9.2.26, 10.2.19; Crowd Data Center 6.3.7, 7.0.3, 7.1.1, 7.2.4; Jira Software Data Center 9.12.40, 10.3.26, 11.3.12; Jira Service Management Data Center 5.12.40, 10.3.26, 11.3.12; Bamboo Data Center 10.2.24, 12.1.12; Crucible 4.9.15; Fisheye 4.9.15

## Technical details

An arbitrary file access vulnerability in multiple Atlassian Data Center products permits unauthenticated remote attackers to read specific files within the web application root directory. Exploitation requires prior knowledge of the target file's exact path and name; directory enumeration is not possible. Depending on deployment configuration, sensitive files in the web root could lead to authentication bypass, credential exposure, or system compromise.

## Affected products

- Atlassian Bitbucket Data Center 4.6.0 and later
- Atlassian Confluence Data Center 5.10.0 and later
- Atlassian Jira Software Data Center 7.1.0 and later
- Atlassian Jira Service Management Data Center 3.1.0 and later
- Atlassian Bamboo Data Center 7.0.1 and later
- Atlassian Crowd Data Center 2.11.0 and later
- Atlassian Crucible all
- Atlassian Fisheye all

## Timeline

- 2026-10-05: disclosed

## Related threats

- [Atlassian Confluence Data Center DoS in authenticated request handling](https://junglewise.ai/threats/cve-2026-21588-atlassian-confluence-data-center-dos-in-authenticated-request)
- [Atlassian Jira Service Management Data Center improper authorization](https://junglewise.ai/threats/cve-2026-21587-atlassian-jira-service-management-data-center-improper)
- [Atlassian Confluence Data Center improper authorization](https://junglewise.ai/threats/cve-2026-21586-atlassian-confluence-data-center-improper-authorization)
- [Atlassian Confluence Data Center information disclosure](https://junglewise.ai/threats/cve-2026-21579-atlassian-confluence-data-center-information-disclosure)
- [Atlassian Confluence Data Center denial of service](https://junglewise.ai/threats/cve-2026-21577-atlassian-confluence-data-center-denial-of-service)