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Vulnerability record · CVE-2026-21586 · published 15 September 2026

CVE-2026-21586: Improper authorization vulnerability

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.

7.1 CVSS 4.0 High EPSS 0.32% · top 77.1% CWE-285 · Improper authorization Awaiting Analysis
7.1CVSS 4.0 base score
0.32%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
2References
17 Sep 2026Last modified by NVD

Description

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.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/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:

References

LinkTags
https://confluence.atlassian.com/pages/viewpage.action?pageId=1822852209
https://jira.atlassian.com/browse/CONFSERVER-104418

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.8CVE-2026-58704Android Cellular Modem improper authorization allows adjacent privilege escalationAndroid's Cellular Modem component contains a logic error that bypasses permission checks, allowing an attacker within radio/adjacent range to escala…KEVEPSS 0.59%analysed9.8CVE-2021-28799QNAP HBS 3 improper authorization allows remote loginQNAP Hybrid Backup Sync 3 (HBS 3) contains an improper authorization flaw that lets remote attackers log in to the NAS device. The issue affects mult…KEVEPSS 78%analysed

Source: NIST National Vulnerability Database (record CVE-2026-21586), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.