CVEs / CVE-2026-21589
CVE-2026-21589: Atlassian Multiple Products Files or Directories Accessible to External Parties Vulnerability
- Known exploited in the CISA KEV catalog since 15 Oct 2026
- high 7.5 CVSS 3.1 (NVD)
- EPSS 99.4% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Multiple Atlassian products (Bitbucket Data Center ,Confluence Data Center, Jira Service Management Data Center, Jira Software Data Center, Bamboo Data Center, Crowd Data Center, Crucible and Fisheye) contain a files or directories accessible to external parties vulnerability which could allow an unauthenticated attacker to access specific files within the web application root directory in affected versions.
Description
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Atlassian Bamboo Data Center | All other versions | — |
| Atlassian Bitbucket Data Center | All other versions | — |
| Atlassian Confluence Data Center | All other versions | — |
| Atlassian Crowd Data Center | All other versions | — |
| Atlassian Crucible Data Center | All other versions | — |
| Atlassian Fisheye Data Center | All other versions | — |
| Atlassian Jira Service Management Data Center | All other versions | — |
| Atlassian Jira Software Data Center | All other versions | — |
Exploitation
| In CISA KEV since | 15 Oct 2026 |
|---|---|
| Due date for US federal agencies | 18 Oct 2026 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. |
Severity
| CVSS 3.1 | 7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NScored by NVD |
|---|---|
| Weakness | CWE-552 |
References
- CVE-2026-21589 on NVD
- CVE-2026-21589 in the CISA KEV catalog
- https://confluence.atlassian.com/security/cve-2026-21589-arbitrary-file-access-vulnerability-impacts-multiple-products-1870495748.html?ref=labs.watchtowr.com (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- https://jira.atlassian.com/browse/BAM-26567 Issue Tracking, Mitigation, Vendor Advisory
- https://jira.atlassian.com/browse/BSERV-20604 Issue Tracking, Mitigation, Vendor Advisory
- https://jira.atlassian.com/browse/CONFSERVER-104488 Issue Tracking, Mitigation, Vendor Advisory
- https://jira.atlassian.com/browse/CRUC-8741 Issue Tracking, Mitigation, Vendor Advisory
- https://jira.atlassian.com/browse/CWD-6610 Issue Tracking, Mitigation, Vendor Advisory
- https://jira.atlassian.com/browse/FE-7583 Issue Tracking, Mitigation, Vendor Advisory
- https://jira.atlassian.com/browse/JRASERVER-79546 Issue Tracking, Mitigation, Vendor Advisory
- https://jira.atlassian.com/browse/JSDSERVER-16809 Issue Tracking, Mitigation, Vendor Advisory
- https://github.com/watchtowrlabs/watchTowr-vs-Atlassian-CVE-2026-21589 Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21589 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.