CVE-2026-21589

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure.

In the wild

CISA lists this as exploited in real attacks. Treat as urgent.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-01-01 00:00 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-10-05 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-10-15 Exploited in the wildAdded to CISA's Known Exploited Vulnerabilities list
4. 2026-10-18 Remediation deadlineCISA's due date for federal agencies to fix it
5. 2026-10-29 13:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: yes, CISA lists it. This puts it above everything that is not.
• Exploit odds: 99.7% in the next 30 days (EPSS).
• Severity: 9.3 CRITICAL (CVSS).
• Fix: a patch or advisory is linked.
• It meets the bar for Drop everything: critical, and exploited or very likely to be.

Details

Published

2026-10-05 22:16 UTC

Last modified

2026-10-29 13:17 UTC

Added to CISA KEV

2026-10-15

Exploit probability

99.7% · EPSS, next 30 days

Weakness

CWE-552

Record status

Analyzed

Affected

• Atlassian Bitbucket Data Center < 9.4.26
• Atlassian Bitbucket Data Center < 10.2.8
• Atlassian Bitbucket Data Center < 10.5.1
• Atlassian Bitbucket Server ≤ 8.14.6
• Atlassian Confluence Data Center < 9.2.26
• Atlassian Confluence Data Center < 10.2.19
• Atlassian Crowd < 6.3.7
• Atlassian Crowd < 7.0.3

Attack profile CVSS 4.0 · 9.3

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

None

User interaction

None

Confidentiality

High

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-21589.md and follow it. Check whether this project is affected by CVE-2026-21589. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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