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Vulnerability record · CVE-2026-16443 · published 5 August 2026

CVE-2026-16443: Redhat build of keycloak improper verification of cryptographic signature vulnerability

Redhat · Build Of Keycloak

A flaw was found in the SAML metadata import functionality of the keycloak-services component, which is the core engine for identity brokering in Red Hat Build of Keycloak. When importing identity provider metadata that lacks specific usage attributes for keys, the system incorrectly disables signature validation for SAML responses even if a signing certificate is provided. This issue allows an unauthenticated attacker to forge a SAML response and gain unauthorized access to a user account by knowing their external identifier.

9.1 CVSS 3.1 Critical EPSS 0.26% · top 84.7% CWE-347 · Improper verification of cryptographic signature
9.1CVSS 3.1 base score
0.26%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References
10 Aug 2026Last modified by NVD

Description

A flaw was found in the SAML metadata import functionality of the keycloak-services component, which is the core engine for identity brokering in Red Hat Build of Keycloak. When importing identity provider metadata that lacks specific usage attributes for keys, the system incorrectly disables signature validation for SAML responses even if a signing certificate is provided. This issue allows an unauthenticated attacker to forge a SAML response and gain unauthorized access to a user account by knowing their external identifier.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://access.redhat.com/errata/RHSA-2026:50846 Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:50847 Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:50848 Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:50849 Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-16443 Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2503139 Issue TrackingVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-16443), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.