CVE-2026-21582Network attack vector

Unauthenticated user impersonation

Published Aug 18, 2026 · Updated Aug 20, 2026

Authentication bypass in Atlassian Crowd Data Center 7.2.1 allows remote attackers to act as another user via network requests. Atlassian has not disclosed the affected endpoint or session-handling flaw, only that version 7.2.1 accepts requests that run with another user's identity. Exposure is limited to deployments running 7.2.1, and the published impact is impersonation of existing users rather than code execution or service interruption.

CVSS severity8.8
High
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Atlassian Crowd Data Center 7.2.1 allows remote attackers to act as another user via network requests. Atlassian has not disclosed the affected endpoint or session-handling flaw, only that version 7.2.1 accepts requests that run with another user's identity. Exposure is limited to deployments running 7.2.1, and the published impact is impersonation of existing users rather than code execution or service interruption.

The record

CVE
CVE-2026-21582
Published
Aug 18, 2026
Updated
Aug 20, 2026
Vendor
Atlassian
Product
Crowd Data Center
Classifications
CWE-287, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Atlassian · Crowd Data Centerversion=7.2.1

Published CVSS scores

8.8AtlassianCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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