5.3

CVE-2026-9803

Keycloak: keycloak: denial of service via malformed authorization header

A flaw was found in Keycloak's ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed 'Authorization: Bearer' header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Redhat ≫ Build Of Keycloak Version- SwEdition-
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.42% 0.334
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
secalert@redhat.com 5.3 3.9 1.4
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE-125 Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

https://access.redhat.com/security/cve/CVE-2026-9803
Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2482465
Vendor Advisory
Issue Tracking
https://access.redhat.com/errata/RHSA-2026:25098
https://access.redhat.com/errata/RHSA-2026:25097
https://access.redhat.com/errata/RHSA-2026:30049
https://access.redhat.com/errata/RHSA-2026:30050