CVE-2026-16442Network attack vector

Account takeover via unenforced link-only restriction

Published Aug 5, 2026 · Updated Aug 5, 2026

Authentication bypass in Red Hat build of Keycloak 26.4 before 26.4.14 and 26.6 before 26.6.5 allows remote attackers to take over linked accounts. The IdP-initiated SSO handler processes broker logins without enforcing the identity provider's link-only setting. Exploitation requires control of an upstream identity already linked to a local user and yields a full authenticated session for that account.

CVSS severity7.4
High
EPSS probability0.20%
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 Red Hat build of Keycloak 26.4 before 26.4.14 and 26.6 before 26.6.5 allows remote attackers to take over linked accounts. The IdP-initiated SSO handler processes broker logins without enforcing the identity provider's link-only setting. Exploitation requires control of an upstream identity already linked to a local user and yields a full authenticated session for that account.

The record

CVE
CVE-2026-16442
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
389 Directory Server
Product
Red Hat build of Keycloak
Classifications
CWE-346, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

389 Directory Server · Red Hat build of KeycloakAffected versions are unavailable in this record.

Published CVSS scores

7.4Red HatCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-346Origin Validation Error
T1078Valid Accounts

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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