MEDIUM 5.3
GHSA-cpf7-j4cf-vqx4
Keycloak has an Out-of-bounds Read
Details
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.
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Affected packages
Maven / org.keycloak:keycloak-services
Introduced in:
0 No fixed version published yet for org.keycloak:keycloak-services (maven). Pin to a known-safe version or switch to an alternative.
Maven / org.keycloak:keycloak-services
Introduced in:
26.5.0 Fixed in: 26.6.3 Fix
# pom.xml: bump <version>26.6.3</version> for org.keycloak:keycloak-services References
- https://nvd.nist.gov/vuln/detail/CVE-2026-9803 [ADVISORY]
- https://github.com/keycloak/keycloak/issues/49433 [WEB]
- https://github.com/keycloak/keycloak/pull/49500 [WEB]
- https://github.com/keycloak/keycloak/pull/49617 [WEB]
- https://github.com/keycloak/keycloak/pull/49618 [WEB]
- https://github.com/keycloak/keycloak/commit/2b8692499e907e6205be0bd9c8a4da5d46f6ca30 [WEB]
- https://github.com/keycloak/keycloak/commit/3fc06909cc93eb5c4739a712fa350de625812e04 [WEB]
- https://github.com/keycloak/keycloak/commit/ef06df91d344c7e99fcb82987ef6adb854f30789 [WEB]
- https://access.redhat.com/errata/RHSA-2026:25097 [WEB]
- https://access.redhat.com/errata/RHSA-2026:25098 [WEB]
- https://access.redhat.com/errata/RHSA-2026:30049 [WEB]
- https://access.redhat.com/errata/RHSA-2026:30050 [WEB]
- https://access.redhat.com/security/cve/CVE-2026-9803 [WEB]
- https://bugzilla.redhat.com/show_bug.cgi?id=2482465 [WEB]
- https://github.com/keycloak/keycloak [PACKAGE]