Risk Letters

Exploited vulnerability

CVE-2026-21589

TLP:CLEAR

Atlassian Multiple Products Files or Directories Accessible to External Parties Vulnerability

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.

Facts

  • Vendor: Atlassian
  • Product: Multiple Products
  • CVSS: 9.3
  • EPSS (probability of exploitation within 30 days): 99.5 %
  • On CISA's Known Exploited Vulnerabilities list since: 15 October 2026
  • First known exploitation: 7 October 2026
  • CISA's deadline for US federal agencies: 18 October 2026
  • Weakness: CWE-552
  • First seen by Risk Letters: 15 October 2026

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Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD