8.8
HIGH CVSS 4.0
CVE-2026-21582
Atlassian Crowd Data Center Broken Authentication and Session Management Vulnerability
Description

This High severity BASM (Broken Authentication & Session Management) vulnerability known as CVE-2026-21582 was introduced in version 7.2.1 of Crowd Data Center. This BASM (Broken Authentication & Session Management) vulnerability, with a CVSS Score of 8.8, allows an unauthenticated attacker to perform actions as another user. Atlassian recommends that Crowd 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: Crowd Data Center 7.2: Upgrade to a release greater than or equal to 7.2.2 See the release notes (https://confluence.atlassian.com/crowd/crowd-release-notes-199094.html). You can download the latest version of Crowd Data Center from the download center (https://www.atlassian.com/software/crowd/download-archive). This vulnerability was reported via our Penetration Testing program.

INFO

Published Date :

Aug. 18, 2026, 10:16 p.m.

Last Modified :

Aug. 18, 2026, 10:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-21582 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.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 HIGH [email protected]
Solution
Upgrade Crowd Data Center to a fixed version to address authentication bypass.
  • Upgrade Crowd Data Center to the latest version.
  • If unable, upgrade to a supported fixed version.
  • Consult release notes for specific upgrade versions.
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-2026-21582.

URL Resource
https://confluence.atlassian.com/pages/viewpage.action?pageId=1821999768
https://jira.atlassian.com/browse/CWD-6562
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-21582 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-2026-21582 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-2026-21582 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-21582 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': 'Crowd Data Center', 'versions': [{'status': 'affected', 'version': '7.2.1'}, {'status': 'unaffected', 'version': '7.2.2 to 7.2.3'}]}]
    Added Description This High severity BASM (Broken Authentication & Session Management) vulnerability known as CVE-2026-21582 was introduced in version 7.2.1 of Crowd Data Center. This BASM (Broken Authentication & Session Management) vulnerability, with a CVSS Score of 8.8, allows an unauthenticated attacker to perform actions as another user. Atlassian recommends that Crowd 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: Crowd Data Center 7.2: Upgrade to a release greater than or equal to 7.2.2 See the release notes (https://confluence.atlassian.com/crowd/crowd-release-notes-199094.html). You can download the latest version of Crowd Data Center from the download center (https://www.atlassian.com/software/crowd/download-archive). This vulnerability was reported via our Penetration Testing program.
    Added CVSS V4.0 AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/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/CWD-6562
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.