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

CVE-2026-21589 is rated critical with a CVSS v4.0 base score of 9.3 and affects Atlassian Multiple Products, along with 3 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. CISA added it to its Known Exploited Vulnerabilities catalog on 2026-10-15, which means exploitation in the wild has been observed.

Vulnerability description

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.

Severity breakdown

CVSS v4.0 9.3: 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

  • Attack vector: Network. Exploitable remotely over the network.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Attack requirements: None. No deployment or execution conditions are needed.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Confidentiality impact (vulnerable system): High. Total loss of confidentiality.
  • Integrity impact (vulnerable system): None. No loss of integrity.
  • Availability impact (vulnerable system): None. No effect on availability.
  • Confidentiality impact (subsequent systems): High. Total loss of confidentiality on other systems.
  • Integrity impact (subsequent systems): High. Total loss of integrity on other systems.
  • Availability impact (subsequent systems): High. Total loss of availability of other systems.

Underlying weakness

CWE-552: Files or Directories Accessible to External Parties

The product makes files or directories accessible to unauthorized actors, even though they should not be.

Affected products

  • Atlassian Bitbucket Data Center: from 7.17.0 before 9.4.26; from 9.5.0 before 10.2.8; from 10.3.0 before 10.5.1
  • Atlassian Confluence Data Center: from 5.10.0 before 9.2.26; from 9.3.0 before 10.2.19
  • Atlassian Crowd: from 2.11.0 before 6.3.7; from 7.0.0 before 7.0.3; from 7.1.0 before 7.1.7; from 7.2.0 before 7.2.4
  • Atlassian Jira Service Management: from 4.14.0 before 5.12.40; from 5.13.0 before 10.3.26; from 10.4.0 before 11.3.12
  • Atlassian Bamboo: from 7.0.1 before 10.2.24; from 11.0.0 before 12.1.12
  • Atlassian Crucible: before 4.9.15
  • Atlassian Fisheye: before 4.9.15
  • Atlassian Bitbucket Server: from 4.6.0 up to and including 8.14.6
  • Atlassian Jira Data Center: from 7.1.0 before 9.12.40; from 9.13.0 before 10.3.26; from 10.4.0 before 11.3.12
  • Atlassian Jira Service Desk: from 3.1.0 up to and including 4.13.27

References