TI-2026-17407 Aliases CVE-2026-21586 GHSA-qjg9-922r-8886

Improper authorization in Atlassian Confluence Data Center

LOW 34CWE-285Published 2026-09-15 · Updated 2026-09-17

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Security bypass
Confidentiality · integrity · availability: High · None · None
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-285.

Summary

This High severity Improper Authorization vulnerability was introduced in versions 7.4.0, 7.13.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0, and 10.2.0 of Confluence Data Center. This Improper Authorization vulnerability, with a CVSS Score of 7.1, allows an authenticated attacker to gain unintended access and can lead to the exposure of resources or functionality, possibly providing attackers with sensitive information or even execute arbitrary code. Atlassian recommends that Confluence Data Center customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions: Confluence Data Center 9.2: Upgrade to a release greater than or equal to 9.2.24 Confluence Data Center 10.2: Upgrade to a release greater than or equal to 10.2.17 See the release notes ([https://confluence.atlassian.com/doc/confluence-release-notes-327.html]). You can download the latest version of Confluence Data Center from the download center ([https://www.atlassian.com/software/confluence/download-archives]). This vulnerability was reported via our Penetration Testing program.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00445 38th percentileScored 2026-11-07

Fix Fixed Confluence Data Center (Atlassian): 10.2.17 to 10.2.18, 9.2.24 to 9.2.25

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Atlassian	Confluence Data Center	10.2.1 to 10.2.15; 10.1.0 to 10.1.2; 10.0.2 to 10.0.3; 9.5.1 to 9.5.4; 9.4.0 to 9.4.1; 9.3.1 to 9.3.2; 9.2.0 to 9.2.23; 9.1.1; 8.9.7 to 8.9.8; 8.5.16 to 8.5.31; 7.19.28 to 7.19.30	10.2.17 to 10.2.18, 9.2.24 to 9.2.25	Patch available	CNA

Confluence Data Center VendorAtlassian Affected 10.2.1 to 10.2.15; 10.1.0 to 10.1.2; 10.0.2 to 10.0.3; 9.5.1 to 9.5.4; 9.4.0 to 9.4.1; 9.3.1 to 9.3.2; 9.2.0 to 9.2.23; 9.1.1; 8.9.7 to 8.9.8; 8.5.16 to 8.5.31; 7.19.28 to 7.19.30 Fixed in 10.2.17 to 10.2.18, 9.2.24 to 9.2.25 Patch available CNA

Remediation

Fix · CNA Confluence Data Center (Atlassian) Fixed in 10.2.17 to 10.2.18, 9.2.24 to 9.2.25

Timeline

2026-10-02 Threatist record created from CVE-2026-21586
2026-10-03 Alias added: GHSA-qjg9-922r-8886

References

Other 2

TI-2023-08765 Injection in Atlassian Confluence Data Center KEVCVSS 3.1CRITICAL 9.8
TI-2023-08757 Improper input validation in Atlassian Confluence Data Center KEVCVSS 3.1CRITICAL 9.8
TI-2022-09600 Hard-coded credentials in Atlassian Questions For Confluence KEVCVSS 3.1CRITICAL 9.8
TI-2022-09596 Expression language injection in Atlassian Confluence Data Center KEVCVSS 3.1CRITICAL 9.8
TI-2021-08036 Expression language injection in Atlassian Confluence Server KEVCVSS 3.1CRITICAL 9.8
TI-2019-08654 Injection in Atlassian Jira Server and Data Center KEVCVSS 3.1CRITICAL 9.8

See all 477 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences