CVE-2026-21589

critical · 9.3Actively exploited

On the CISA Known Exploited Vulnerabilities catalog

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.

Added 2026-10-15Remediation due 2026-10-18

A public exploit / detection template exists

Weaponised detection is publicly available, which meaningfully raises real-world risk regardless of CVSS. nuclei-templates →

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.

9.3

CVSS

99.5%

EPSS (exploit prob.)

100th

EPSS percentile

2026-10-05

Published

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

Weaknesses

CWE-552

Affected products

Vendor	Product	Affected versions
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

Check a specific version with /api/v1/cve/match.

References

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-21589