Keycloak-services: keycloak-services: saml idp-initiated broker login bypasses link-only restriction
Summary
| CVE | CVE-2026-16442 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-05 16:16:52 UTC |
| Updated | 2026-08-10 19:21:47 UTC |
| Description | A flaw was found in the SAML broker component of Keycloak, which is used to manage identity federation and user authentication. The issue occurs because the IdP-initiated Single Sign-On endpoint fails to check if a provider is restricted to account linking only. This allows an attacker with control over a linked upstream identity to bypass login restrictions and gain full access to a local user account. |
Risk And Classification
Primary CVSS: v3.1 9.8 CRITICAL from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.001890000 probability, percentile 0.087660000 (date 2026-08-09)
Problem Types: CWE-346 | CWE-346 Origin Validation Error
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | [email protected] | Secondary | 7.4 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N |
| 3.1 | CNA | CVSS | 7.4 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Redhat | Build Of Keycloak | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Build Of Keycloak 26.4 | unaffected 26.4.14-1 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.4 | unaffected 26.4-22 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.4 | unaffected 26.4-22 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.4.14 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.4.14 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6 | unaffected 26.6.5-1 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6 | unaffected 26.6-11 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6 | unaffected 26.6-11 * rpm | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6.5 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6.5 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak 26.6.5 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Data Grid 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | Not specified | Not specified |
| CNA | Red Hat | Red Hat Single Sign-On 7 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:50846 | [email protected] | access.redhat.com | Vendor Advisory |
| access.redhat.com/errata/RHSA-2026:50847 | [email protected] | access.redhat.com | Vendor Advisory |
| access.redhat.com/errata/RHSA-2026:50848 | [email protected] | access.redhat.com | Vendor Advisory |
| access.redhat.com/errata/RHSA-2026:50849 | [email protected] | access.redhat.com | Vendor Advisory |
| access.redhat.com/security/cve/CVE-2026-16442 | [email protected] | access.redhat.com | Vendor Advisory |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | Issue Tracking, Vendor Advisory |
| 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 Paul Bottinelli (Trail of Bits) for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-07-17T18:19:22.000Z | Reported to Red Hat. |
| CNA | 2026-08-05T02:02:00.000Z | Made public. |
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.
There are currently no legacy QID mappings associated with this CVE.