Keycloak: keycloak: unauthorized authentication via disabled saml identity provider

Summary

CVECVE-2026-2603
StatePUBLISHED
Assignerredhat
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-03-18 02:16:24 UTC
Updated2026-07-15 02:19:31 UTC
DescriptionA flaw was found in Keycloak. A remote attacker could bypass security controls by sending a valid SAML response from an external Identity Provider (IdP) to the Keycloak SAML endpoint for IdP-initiated broker logins. This allows the attacker to complete broker logins even when the SAML Identity Provider is disabled, leading to unauthorized authentication.

Risk And Classification

Primary CVSS: v3.1 8.1 HIGH from ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

EPSS: 0.004130000 probability, percentile 0.335300000 (date 2026-07-18)

Problem Types: CWE-306 | CWE-306 Missing Authentication for Critical Function


VersionSourceTypeScoreSeverityVector
3.1ADPCVSS8.1HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
3.1[email protected]Secondary8.1HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
3.10b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary8.1HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
3.1CNACVSS8.1HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Red Hat Red Hat Build Of Keycloak 26.2 unaffected 26.2.14-1 * rpm Not specified
CNA Red Hat Red Hat Build Of Keycloak 26.2 unaffected 26.2-16 * rpm Not specified
CNA Red Hat Red Hat Build Of Keycloak 26.2 unaffected 26.2-16 * rpm Not specified
CNA Red Hat Red Hat Build Of Keycloak 26.2.14 Not specified Not specified
CNA Red Hat Red Hat Build Of Keycloak 26.4 unaffected 26.4.10-1 * rpm Not specified
CNA Red Hat Red Hat Build Of Keycloak 26.4 unaffected 26.4-12 * rpm Not specified
CNA Red Hat Red Hat Build Of Keycloak 26.4 unaffected 26.4-12 * rpm Not specified
CNA Red Hat Red Hat Build Of Keycloak 26.4.10 Not specified Not specified
ADP Red Hat Red Hat Build Of Keycloak 26.2 unaffected 26.2.14-1 * rpm Not specified
ADP Red Hat Red Hat Build Of Keycloak 26.2 unaffected 26.2-16 * rpm Not specified
ADP Red Hat Red Hat Build Of Keycloak 26.2 unaffected 26.2-16 * rpm Not specified
ADP Red Hat Red Hat Build Of Keycloak 26.2.14 Not specified Not specified
ADP Red Hat Red Hat Build Of Keycloak 26.4 unaffected 26.4.10-1 * rpm Not specified
ADP Red Hat Red Hat Build Of Keycloak 26.4 unaffected 26.4-12 * rpm Not specified
ADP Red Hat Red Hat Build Of Keycloak 26.4 unaffected 26.4-12 * rpm Not specified
ADP Red Hat Red Hat Build Of Keycloak 26.4.10 Not specified Not specified

References

ReferenceSourceLinkTags
bugzilla.redhat.com/show_bug.cgi 134c704f-9b21-4f2e-91b3-4a467353bcc0 bugzilla.redhat.com
access.redhat.com/errata/RHSA-2026:3925 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:3947 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:3948 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/security/cve/CVE-2026-2603 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:3926 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2603.json 0b0ca135-0b70-47e7-9f44-1890c2a1c46c security.access.redhat.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Red Hat would like to thank Joy Gilbert and Reynaldo Immanuel for reporting this issue. (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-02-16T21:15:53.373ZReported to Red Hat.
CNA2026-03-05T11:23:00.000ZMade public.
ADP2026-02-16T21:15:53.373ZReported to Red Hat.
ADP2026-03-05T11:23:00.000ZMade public.

Solutions

ADP: RHSA-2026:3925: Red Hat build of Keycloak 26.2

ADP: RHSA-2026:3948: Red Hat build of Keycloak 26.4

ADP: RHSA-2026:3926: Red Hat build of Keycloak 26.2.14

ADP: RHSA-2026:3947: Red Hat build of Keycloak 26.4.10

Workarounds

CNA: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

ADP: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

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