How to check if you are exposed to CVE-2026-21589
- Find every Atlassian Multiple Products system you or your clients run, including ones exposed to the internet. Those come first: CISA only lists flaws attackers are already using.
- Compare each version with the fixed versions in the vendor advisory below. Where no fix exists yet, apply the vendor’s mitigation or take the system off the internet.
- Run a credentialed vulnerability scan to catch the systems you missed, then check that the next scan no longer reports CVE-2026-21589.
US federal agencies had to fix this by 2026-10-18. Everyone else should treat that deadline as a guide: if it has passed, this is overdue.
Affected versions
Versions the National Vulnerability Database lists as vulnerable to CVE-2026-21589. Check the vendor advisory for the exact fixed builds before you sign anything off.
| Product | Vulnerable versions |
|---|---|
| Atlassian Bitbucket Data Center | from 7.17.0 before 9.4.26; from 9.5.0 before 10.2.8; from 10.3.0 before 10.5.1 |
| Atlassian Bitbucket Server | from 4.6.0 up to and including 8.14.6 |
| Atlassian Confluence Data Center | from 5.10.0 before 9.2.26; from 9.3.0 before 10.2.19 |
| Atlassian Crowd | from 2.11.0 before 6.3.7; from 7.0.0 before 7.0.3; from 7.1.0 before 7.1.7; from 7.2.0 before 7.2.4 |
| Atlassian Jira Data Center | from 7.1.0 before 9.12.40; from 9.13.0 before 10.3.26; from 10.4.0 before 11.3.12 |
| Atlassian Jira Service Desk | from 3.1.0 up to and including 4.13.27 |
NVD lists 4 more affected products; see the full record on NVD.
Timeline
- · Published in the National Vulnerability Database
- · Added to CISA's Known Exploited Vulnerabilities catalog, 10 days after it was published
- · Fix-by date for US federal agencies, passed 14 days ago
Vendor advisories and fixes
Weakness type
More exploited Atlassian vulnerabilities
CISA lists 14 exploited Atlassian vulnerabilities. The closest matches:
- CVE-2021-26086Atlassian Jira Server and Data Center Path Traversal VulnerabilityAdded 2024-11-12
- CVE-2023-22527Atlassian Confluence Data Center and Server Template Injection VulnerabilityAdded 2024-01-24
- CVE-2023-22518Atlassian Confluence Data Center and Server Improper Authorization VulnerabilityAdded 2023-11-07
- CVE-2023-22515Atlassian Confluence Data Center and Server Broken Access Control VulnerabilityAdded 2023-10-05
- CVE-2022-36804Atlassian Bitbucket Server and Data Center Command Injection VulnerabilityAdded 2022-09-30
- CVE-2022-26138Atlassian Questions For Confluence App Hard-coded Credentials VulnerabilityAdded 2022-07-29
- CVE-2022-26134Atlassian Confluence Server and Data Center Remote Code Execution VulnerabilityAdded 2022-06-02
- CVE-2021-26085Atlassian Confluence Server Pre-Authorization Arbitrary File Read VulnerabilityAdded 2022-03-28
Keep going
Sources: CISA Known Exploited Vulnerabilities catalog (version 2026.10.30); EPSS data from FIRST.org; CVSS and descriptions from the NIST National Vulnerability Database. Checked 2026-11-01. This product uses the NVD API but is not endorsed or certified by the NVD.
