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Severe, 6 weeks1496Projects326

1496 severe, 6 weeks · 326 projects

AtlassianCVE-2026-21580

Atlassian Confluence: cross-site scripting

Atlassian

CVE-2026-21580 · Published Aug 18, 2026 · updated Nov 9, 2026

Critical9.3
No fix yet
Atlassian advisory

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.

Affected versions

PackageAffectedFixed in
Confluence Data Center
Product
<= 10.2.0 to 10.2.11No fix yet
<= 10.1.0 to 10.1.2No fix yet
<= 10.0.2 to 10.0.3No fix yet
<= 9.5.1 to 9.5.4No fix yet
Confluence Server
Product
<= 8.5.15 to 8.5.31No fix yet
<= 7.19.27 to 7.19.30No fix yet
Details and references
CVSS 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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:X/V:X/RE:X/U:X
Severity from
the vendor (its own CVE record or advisory)
Weakness
CWE-79

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