CVEvulnerability

CVE-2026-21589

9.3 CRITICAL Known exploited Published 2026-10-05 Modified 2026-10-29 Official page ↗

CISA Known Exploited Vulnerability

Atlassian Multiple Products Files or Directories Accessible to External Parties Vulnerability — Atlassian Multiple Products

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
Remediation due: 2026-10-18
Ransomware use: Unknown
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.
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

Status: Analyzed
Published: 2026-10-05
Last modified: 2026-10-29
Assigner: [email protected]
CVSS 4.0 ([email protected]): 9.3 CRITICAL — 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
CVSS 3.1 ([email protected]): 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weaknesses: CWE-552

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.

Affected configurations

• atlassian bitbucket data center (>= 7.17.0 < 9.4.26) • atlassian bitbucket data center (>= 9.5.0 < 10.2.8) • atlassian bitbucket data center (>= 10.3.0 < 10.5.1) • atlassian bitbucket server (>= 4.6.0 <= 8.14.6) • atlassian confluence data center (>= 5.10.0 < 9.2.26) • atlassian confluence data center (>= 9.3.0 < 10.2.19) • atlassian crowd (>= 2.11.0 < 6.3.7) • atlassian crowd (>= 7.0.0 < 7.0.3) • atlassian crowd (>= 7.1.0 < 7.1.7) • atlassian crowd (>= 7.2.0 < 7.2.4) • atlassian jira data center (>= 7.1.0 < 9.12.40) • atlassian jira data center (>= 9.13.0 < 10.3.26) • atlassian jira data center (>= 10.4.0 < 11.3.12) • atlassian jira service desk (>= 3.1.0 <= 4.13.27) • atlassian jira service management (>= 4.14.0 < 5.12.40) • atlassian jira service management (>= 5.13.0 < 10.3.26) • atlassian jira service management (>= 10.4.0 < 11.3.12) • atlassian bamboo (>= 7.0.1 < 10.2.24) • atlassian bamboo (>= 11.0.0 < 12.1.12) • atlassian crucible (< 4.9.15) • atlassian fisheye (< 4.9.15)

Weakness · CWE (1)

CWE-552 Files or Directories Accessible to External Parties weakness

References