Patch nowWhy this label: EPSS >99%

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

Product: Atlassian Multiple Products
Added to CISA KEV: October 15, 2026
Deadline for US federal agencies: October 18, 2026
Known ransomware use: Not known
EPSS, next 30 days: >99%, in the top 1% of scored CVEs (Oct 25, 2026)
Weakness: CWE-552

What CISA says

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.

What CISA asks you to do

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.

Sources

Also exploited recently

Data from CISA's Known Exploited Vulnerabilities catalog (public domain) and FIRST EPSS, refreshed hourly. Rheono did not find or test this vulnerability; this page summarizes public sources.