Rising fast KEV catalog No authentication
CVE-2026-21589

Atlassian Multiple Products Files or Directories Accessible to External Parties Vulnerability

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…

CheckOps priority index
9.1/10 Patch within 24 h
Severity9.3
Probability9.9
Exploitation4/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 99.5% higher than 99.9% of CVEs
CVSS 4.0 9.3 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/
Exploited for 19 days 15 Oct 2026
CISA due date 18 Oct 2026 for US federal agencies

Exploitation probability EPSS · FIRST

05010006 Oct12 Oct21 Oct27 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 4 / 5

  • KEV catalog (CISA)15 Oct 2026
  • Exploited in EUVD (ENISA)15 Oct 2026
  • Used by ransomwareno
  • EPSS above 10 %99.5%
  • No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: 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.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

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 products

Bitbucket Data CenterCrucible Data CenterBamboo Data CenterConfluence Data CenterJira Software Data CenterJira Service Management Data CenterFisheye Data CenterCrowd Data CenterMultiple Products
Affected versions
  • All other versions
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

  5. EPSS peak: 99.5%

References

Other exploited vulnerabilities from the same vendor

  • CVE-2021-26086Atlassian Jira Server and Data Center Path Traversal Vulnerability
    7.5 · Background exploitation
  • CVE-2023-22527Atlassian Confluence Data Center and Server Template Injection Vulnerability
    10.0 · Background exploitation
  • CVE-2023-22518Atlassian Confluence Data Center and Server Improper Authorization Vulnerability
    10.0 · Background exploitation
  • CVE-2023-22515Atlassian Confluence Data Center and Server Broken Access Control Vulnerability
    10.0 · Background exploitation
  • CVE-2022-36804Atlassian Bitbucket Server and Data Center Command Injection Vulnerability
    8.3 · Background exploitation
  • CVE-2022-26138Atlassian Questions For Confluence App Hard-coded Credentials Vulnerability
    9.3 · Background exploitation

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities