Skip to content
Log inStart free trial

CVE-2026-21589

This is a vulnerability in Bitbucket Data Center, Confluence Data Center, Jira Service Management Data Center, Jira Software Data Center, Bamboo Data Center.

Critical Known exploited
Severity
9.3 / 10
Critical · CVSS 4.0
Exploit chance (EPSS)
99.48%
Chance of exploitation in the next 30 days. Higher than 99.94% of scored vulnerabilities.
Known exploited
Yes
In CISA's catalog since Oct 15, 2026
Weakness
CWE-552 Files or Directories Accessible to External Parties
Fix
None yet
No fixed version published
Exploited in the wild. Atlassian Multiple Products Files or Directories Accessible to External Parties Vulnerability (Atlassian Multiple Products). 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. Due for U.S. federal agencies by Oct 18, 2026.

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.

How to fix

No fixed version has been published yet. Until one is, remove or replace the package, or turn off or isolate the affected feature. This page updates when a fix ships.

Severity breakdown

CVSS 4.0 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
Attack complexity
Low
Attack requirements
None
Privileges required
None
User interaction
None
Confidentiality (vulnerable system)
High
Integrity (vulnerable system)
None
Availability (vulnerable system)
None
Confidentiality (subsequent systems)
High
Integrity (subsequent systems)
High
Availability (subsequent systems)
High
Exploit maturity
Not defined
Scope
X

CVSS 3.1 7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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.

How to prevent it
  • Implementation, System Configuration, Operation: 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.

References

Advisories

Other links

Timeline

  1. Published
  2. Added to CISA's Known Exploited Vulnerabilities catalog
  3. Remediation due for U.S. federal agencies
  4. Last updated by the source
  5. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-6cr4-ccf3-x7h4
MCP Atlassian: Arbitrary file read via confluence_upload_attachment allows exfiltration of server credentials
High Same weakness, CWE-552
GHSA-4wwp-f6gw-6qm5
SiYuan: TLS Private Keys Readable via getFile (Incomplete Blocklist)
High Same weakness, CWE-552
GHSA-gxcp-jjxh-rwp4
Grafana: SQL Expressions Read File From Disk
Medium Same weakness, CWE-552
GHSA-p58c-q354-6c4f
pgAdmin 4 contains local file inclusion (LFI) and server-side request forgery (SSRF) vulnerabilities
Medium Same weakness, CWE-552
GHSA-57gh-m6rq-54cf
OpenClaw: Self-Whitelisting in appendLocalMediaParentRoots Allows Arbitrary File Read & Credential Exfiltration
Medium Same weakness, CWE-552
GHSA-h2jq-g4cq-5ppq
Rack::Static prefix matching can expose unintended files under the static root
High Same weakness, CWE-552
GHSA-m273-6v24-x4m4
Picklescan vulnerable to Arbitrary File Writing
Critical Same weakness, CWE-552
GHSA-hfv2-pf68-m33x
Umbraco Vulnerable to Improper File Access and Credential Exposure in Dictionary Import Functionality
Medium Same weakness, CWE-552
Is this in your code?

MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.

Check your repos with MergeHarbor