CVE-2026-21589 - Jira/Confluence/Bitbucket Arbitrary File Read

CVE-2026-21589 - Jira/Confluence/Bitbucket Arbitrary File Read

Detection in Action

Detection Artifact Generator attempts to check if the target is vulnerable to CVE-2026-21589. Detection is implemented for following products:

• Atlassian Jira
• Atlassian Confluence
• Atlassian Bitbucket

You need to provide following inputs:

• -H - target host.

Sample run against vulnerable Jira instance:

$ python3 watchTowr-vs-Atlassian-CVE-2026-21589.py -H http://jira.lab.local:8080
                         __         ___  ___________                   
         __  _  ______ _/  |__ ____ |  |_\__    ____\____  _  ________ 
         \ \/ \/ \__  \    ___/ ___\|  |  \|    | /  _ \ \/ \/ \_  __ \
          \     / / __ \|  | \  \___|   Y  |    |(  <_> \     / |  | \/
           \/\_/ (____  |__|  \___  |___|__|__  | \__  / \/\_/  |__|   
                                  \/          \/     \/                            
          
        watchTowr-vs-Atlassian-CVE-2026-21589.py
        (*) CVE-2026-21589 - Jira/Confluence/Bitbucket Arbitrary File Read Detection Artifact Generator

          - Piotr | Sonny | Yordan of watchTowr (@watchTowrcyber)

[+] Starting CVE-2026-21589 DAG
[+] Attempting to send payloads for Jira, Confluence and Bitbucket
[+] Found VULNERABLE Jira instance

Sample run against patched instance:

$ python3 watchTowr-vs-Atlassian-CVE-2026-21589.py -H http://jirapatch.lab.local:8080
                         __         ___  ___________                   
         __  _  ______ _/  |__ ____ |  |_\__    ____\____  _  ________ 
         \ \/ \/ \__  \    ___/ ___\|  |  \|    | /  _ \ \/ \/ \_  __ \
          \     / / __ \|  | \  \___|   Y  |    |(  <_> \     / |  | \/
           \/\_/ (____  |__|  \___  |___|__|__  | \__  / \/\_/  |__|   
                                  \/          \/     \/                            
          
        watchTowr-vs-Atlassian-CVE-2026-21589.py
        (*) CVE-2026-21589 - Jira/Confluence/Bitbucket Arbitrary File Read Detection Artifact Generator

          - Piotr | Sonny | Yordan of watchTowr (@watchTowrcyber)

[+] Starting CVE-2026-21589 DAG
[+] Attempting to send payloads for Jira, Confluence and Bitbucket
[-] Unknown response - probably NOT VULNERABLE

Description

This script attempts to detect if Jira/Confluence/Bitbucket is vulnerable to CVE-2026-21589 Arbitrary File Read vulnerability.

Affected Versions

Full version of affected versions can be found here vendor advisory:

According to the official advisory, patched versions are:

• Bitbucket Data Center

  • 9.4.26
  • 10.2.8
  • 10.5.1

• Confluence Data Center

  • 9.2.26
  • 10.2.19

• Jira Service Management Data Center

  • 5.12.40
  • 10.3.26
  • 11.3.12

• Jira Software Data Center

  • 9.12.40
  • 10.3.26
  • 11.3.12

• Bamboo Data Center

  • 10.2.24
  • 12.1.12

• Crowd Data Center

  • 6.3.7
  • 7.0.3
  • 7.1.7
  • 7.2.4

• Crucible

  • 4.9.15

• Fisheye

  • 4.9.15

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• https://labs.watchtowr.com/

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