Coverage › CVE-2026-21589
CVE-2026-21589 Unmapped
Atlassian Multiple Products Files or Directories Accessible to External Parties Vulnerability
- Vendor / product
- Atlassian — Multiple Products
- Description (CISA)
- 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.
- Added to KEV
- 2026-10-15 — after the latest CTID mapping snapshot (2025-07-28)
- Due date
- 2026-10-18
- 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.
- Known ransomware use
- Unknown
- Forensic triage (CISA)
- Yes
- CWE
- CWE-552
- CISA 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 - Elsewhere
- cve.org · NVD · CISA KEV · JSON
ATT&CK techniques
No public source states how this vulnerability is exploited in ATT&CK terms.
The only authoritative CVE → ATT&CK mapping in the open — CTID's Mappings Explorer, pinned to a KEV snapshot of 2025-07-28 and ATT&CK 16.1 — does not include CVE-2026-21589. This entry was added to KEV on 2026-10-15, after that snapshot; of the 357 entries added since, 0 have a mapping. CISA's catalogue carries no technique field. kevmap does not infer techniques from the CWE (CWE-552) — here is why — and does not guess.
This page will change state automatically if a mapping is published. What is shown above is everything CISA publishes about the entry.