Keycloak has an Out-of-bounds Read
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.
01
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-9803US | — | — | ||
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… | ||||
02
references
External citations — patches, advisories, analysis.
- https://access.redhat.com/errata/RHSA-2026:25097WEB
- https://access.redhat.com/errata/RHSA-2026:25098WEB
- https://access.redhat.com/errata/RHSA-2026:30049WEB
- https://access.redhat.com/errata/RHSA-2026:30050WEB
- https://access.redhat.com/security/cve/CVE-2026-9803WEB
- https://bugzilla.redhat.com/show_bug.cgi?id=2482465WEB
- https://github.com/keycloak/keycloakPACKAGE
- https://github.com/keycloak/keycloak/commit/2b8692499e907e6205be0bd9c8a4da5d46f6ca30WEB
scry
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