CVE-2026-21586Network attack vectorHinoki check available

Authenticated resource exposure via undisclosed authorization flaw

Published Sep 15, 2026 · Updated Sep 15, 2026

Improper authorization in Atlassian Confluence Data Center allows remote authenticated users to gain unintended access to protected resources. Atlassian has not published the affected authorization check, request path, or operation that mishandles the authenticated request. A valid account is required; reported outcomes range from sensitive-information exposure to arbitrary code execution, while the reachable resources and execution path remain undisclosed.

CVSS severityUnavailable
Unscored
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper authorization in Atlassian Confluence Data Center allows remote authenticated users to gain unintended access to protected resources. Atlassian has not published the affected authorization check, request path, or operation that mishandles the authenticated request. A valid account is required; reported outcomes range from sensitive-information exposure to arbitrary code execution, while the reachable resources and execution path remain undisclosed.

The record

CVE
CVE-2026-21586
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
Atlassian
Product
Confluence Data Center
Classifications
Unavailable
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 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=10.0.2 to 10.0.3
  2. Affected versionversion=10.1.0 to 10.1.2
  3. Affected versionversion=10.2.1 to 10.2.15
  4. Affected versionversion=7.19.28 to 7.19.30
  5. Affected versionversion=8.5.16 to 8.5.31
  6. Affected versionversion=8.9.7 to 8.9.8
  7. Affected versionversion=9.1.1
  8. Affected versionversion=9.2.0 to 9.2.23
  9. Affected versionversion=9.3.1 to 9.3.2
  10. Affected versionversion=9.4.0 to 9.4.1
  11. Affected versionversion=9.5.1 to 9.5.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Atlassian · Confluence Data Centerversion=10.0.2 to 10.0.3; version=10.1.0 to 10.1.2; version=10.2.1 to 10.2.15; version=7.19.28 to 7.19.30; version=8.5.16 to 8.5.31; version=8.9.7 to 8.9.8; version=9.1.1; version=9.2.0 to 9.2.23; version=9.3.1 to 9.3.2; version=9.4.0 to 9.4.1; version=9.5.1 to 9.5.4

Published CVSS scores

No CVSS assessment is available in this record.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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