CyberSecBulletin
CVE-2026-21589Exploited in the wildNVD status: Analyzed

Atlassian Multiple Products Files or Directories Accessible to External Parties

Published Updated By the CyberSecBulletin desk

CVE-2026-21589 is a high-severity files or directories accessible to external parties vulnerability in Bamboo Data Center from Atlassian, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Bamboo Data Center versions: All other versions. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on October 15, 2026, which means attacks have been observed in the wild.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update Crowd to 6.3.7 or 7.0.3 or 7.1.7 or 7.2.4, whichever matches your release line, or a later version.
  2. Update Jira Data Center to 9.12.40 or 10.3.26 or 11.3.12, whichever matches your release line, or a later version.
  3. Update Jira Service Management to 5.12.40 or 10.3.26 or 11.3.12, whichever matches your release line, or a later version.
  4. CISA's 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.
  5. Read the advisory on jira.atlassian.com for workarounds and exact fixed builds.
  6. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
AtlassianBamboo Data CenterAll other versionsNot stated
AtlassianBitbucket Data CenterAll other versionsNot stated
AtlassianConfluence Data CenterAll other versionsNot stated
AtlassianCrowd Data CenterAll other versionsNot stated
AtlassianCrucible Data CenterAll other versionsNot stated
AtlassianFisheye Data CenterAll other versionsNot stated
AtlassianJira Service Management Data CenterAll other versionsNot stated
AtlassianJira Software Data CenterAll other versionsNot stated
AtlassianBitbucket Server4.6.0 through 8.14.6Not stated
AtlassianCrowd2.11.0 up to, but not including, 6.3.7; 7.0.0 up to, but not including, 7.0.3; 7.1.0 up to, but not including, 7.1.7; 7.2.0 up to, but not including, 7.2.46.3.7, 7.0.3, 7.1.7, 7.2.4
AtlassianJira Data Center7.1.0 up to, but not including, 9.12.40; 9.13.0 up to, but not including, 10.3.26; 10.4.0 up to, but not including, 11.3.129.12.40, 10.3.26, 11.3.12
AtlassianJira Service Desk3.1.0 through 4.13.27Not stated
AtlassianJira Service Management4.14.0 up to, but not including, 5.12.40; 5.13.0 up to, but not including, 10.3.26; 10.4.0 up to, but not including, 11.3.125.12.40, 10.3.26, 11.3.12
AtlassianBamboo7.0.1 up to, but not including, 10.2.24; 11.0.0 up to, but not including, 12.1.1210.2.24, 12.1.12
AtlassianCruciblebefore 4.9.154.9.15
AtlassianFisheyebefore 4.9.154.9.15

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.09.3CriticalCNA (atlassian.com)
CVSS 3.17.5HighNVD

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Files or Directories Accessible to External Parties

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

How developers prevent this class of flaw

  • When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to disable public access.

More Files or Directories Accessible to External Parties vulnerabilities (CWE-552)

Timeline

  1. CVE record published.
  2. Added to CISA's Known Exploited Vulnerabilities catalogue.
  3. CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
  4. Deadline for US federal agencies to remediate, set by CISA.
  5. Record last changed materially (score, affected products, status or references).

References

Advisories

Our coverage

Other vulnerabilities in Bamboo Data Center

All Bamboo Data Center vulnerabilities

Recent Files or Directories Accessible to External Parties vulnerabilities

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