SEPTEMBER 17, 2026
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Case File

CVE-2026-21580

CRITICAL · CVSS 9.3 EPSS 0.40%

Source: NVD + CISA KEV + EPSS · Published 2026-08-18 · Last synced 2026-09-17

CyberRota Analysis

AI-Generated

A critical Stored XSS and Privilege Escalation vulnerability affects multiple versions of Confluence Data Center and Server, enabling unauthenticated attackers to execute arbitrary code in users' browsers and gain elevated privileges. Organizations using the affected versions should prioritize immediate upgrades to the latest releases or specified fixed versions to mitigate the risk of exploitation. This issue is particularly urgent for those handling sensitive data or operating in regulated environments.

CVE
CVE-2026-21580
Severity
CRITICAL
CVSS
9.3
EPSS
0.40%
Java

Original NVD Description

This Critical severity Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability was introduced in versions 7.1.1, 7.4.0, 7.13.0, 7.17.0, 7.19.0, 8.0.0, 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 and Server. This Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability, with a CVSS Score of 8.6, allows an unauthenticated attacker to execute arbitrary HTML or JavaScript code on a victims browser, perform actions as a higher-privileged user, and to get into the system utilizing loopholes exposed from security best-practices being overlooked. Atlassian recommends that Confluence Data Center and Server 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 and Server 9.2: Upgrade to a release greater than or equal to 9.2.21 Confluence Data Center and Server 10.2: Upgrade to a release greater than or equal to 10.2.13 See the release notes ([https://confluence.atlassian.com/doc/confluence-release-notes-327.html]). You can download the latest version of Confluence Data Center and Server from the download center ([https://www.atlassian.com/software/confluence/download-archives]). This vulnerability was reported via our Bug Bounty program.