CVE-2026-21589Atlassian Multiple Products Files or Directories Accessible to External Parties Vulnerability

BOD 26-04 remediation window

With CISA's SSVC answers for this CVE (automatable: no, technical impact: total), BOD 26-04 Table 1 gives 3 days and forensic triage on a publicly exposed asset (row 3) and 14 days on an asset that is not publicly exposed (row 11) ^S06. CISA set the catalogue due date at 3 days; under BOD 26-04 it reflects CISA's own view of whether the flaw sits on publicly exposed assets ^S07. The directive binds US federal civilian executive branch agencies only.

What CISA says

Short description

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.

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.

Notes

https://confluence.atlassian.com/security/cve-2026-21589-arbitrary-file-access-vulnerability-impacts-multiple-products-1870495748.html?ref=labs.watchtowr.com ; ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-21589

CWE in the catalogue

CWE-552

Official links

• CISA KEV catalogue entry cisa.gov
• NVD record nvd.nist.gov

Vendor advisory and patch links

References NVD tags Vendor Advisory or Patch, exactly as NVD lists them.

• 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

Links in CISA's notes

• https://confluence.atlassian.com/security/cve-2026-21589-arbitrary-file-access-vulnerability-impacts-multiple-products-1870495748.html?ref=labs.watchtowr.com
• https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
• https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
• https://nvd.nist.gov/vuln/detail/CVE-2026-21589

NVD details

CWE (NVD)

CWE-552 by CISA ADP

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS versions in NVD

V31, V40

Last modified in NVD

2026-10-29T13:17:09.847

Where each value comes from

This product uses data from the NVD API but is not endorsed or certified by the NVD. CISA does not endorse Sysprobs. Methodology.