Keycloak Vulnerable to Improper Validation of Specified Quantity in Input
A flaw was found in Keycloak. A remote attacker with high privileges, such as a realm administrator configuring a malicious Lightweight Directory Access Protocol (LDAP) server or an attacker compromising an upstream LDAP server, could exploit this vulnerability. By sending a malformed LDAP password policy response during a password authentication request, the attacker can trigger an OutOfMemoryError. This causes the Keycloak Java Virtual Machine (JVM) to terminate, leading to a denial of service (DoS) for all realms on the affected node.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-9801US | — | — | ||
A flaw was found in Keycloak. A remote attacker with high privileges, such as a realm administrator configuring a malicious Lightweight Directory Access Protocol (LDAP) server or a… | ||||
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-2026-9801WEB
- https://bugzilla.redhat.com/show_bug.cgi?id=2482473WEB
- https://github.com/keycloak/keycloakPACKAGE
- https://github.com/keycloak/keycloak/commit/2c4fe42235ba8c265b1da3a30541a270d5bd8c39WEB
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