CVE-2026-21582: atlassian crowd data center Improper Authentication

Vulnerability summary

CVE-2026-21582 is a high (CVSS 8.8) Improper Authentication vulnerability in atlassian crowd data center. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 40.1% of scored vulnerabilities.

Timeline

1. 18-08-2026
   PublishedVulnerability first disclosed.
2. 20-08-2026
   Last modifiedVulnerability information updated.

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.

• CWE-287Improper AuthenticationWhen an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.