CVE-2026-21580
Atlassian Confluence Data Center and Server Stored Cross-Site Scripting, Privilege Escalation, and Security Misconfiguration
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.
INFO
Published Date :
Aug. 18, 2026, 10:16 p.m.
Last Modified :
Aug. 18, 2026, 10:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-21580
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Upgrade to the latest version.
- Upgrade to a fixed release version.
- Review security best practices.
- Apply vendor security patches.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-21580.
| URL | Resource |
|---|---|
| https://confluence.atlassian.com/pages/viewpage.action?pageId=1821999768 | |
| https://jira.atlassian.com/browse/CONFSERVER-104381 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-21580 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-21580
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-21580 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-21580 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 18, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Atlassian', 'product': 'Confluence Data Center', 'versions': [{'status': 'affected', 'version': '10.2.0 to 10.2.11'}, {'status': 'affected', 'version': '10.1.0 to 10.1.2'}, {'status': 'affected', 'version': '10.0.2 to 10.0.3'}, {'status': 'affected', 'version': '9.5.1 to 9.5.4'}, {'status': 'affected', 'version': '9.4.0 to 9.4.1'}, {'status': 'affected', 'version': '9.3.1 to 9.3.2'}, {'status': 'affected', 'version': '9.2.0 to 9.2.20'}, {'status': 'affected', 'version': '9.1.0 to 9.1.1'}, {'status': 'affected', 'version': '9.0.3'}, {'status': 'affected', 'version': '8.9.6 to 8.9.8'}, {'status': 'affected', 'version': '8.5.15 to 8.5.31'}, {'status': 'affected', 'version': '7.19.27 to 7.19.30'}, {'status': 'unaffected', 'version': '10.2.13 to 10.2.15'}, {'status': 'unaffected', 'version': '9.2.21 to 9.2.23'}]}, {'vendor': 'Atlassian', 'product': 'Confluence Server', 'versions': [{'status': 'affected', 'version': '8.5.15 to 8.5.31'}, {'status': 'affected', 'version': '7.19.27 to 7.19.30'}]}] Added 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. Added CVSS V4.0 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 Added Reference https://confluence.atlassian.com/pages/viewpage.action?pageId=1821999768 Added Reference https://jira.atlassian.com/browse/CONFSERVER-104381