A flaw was found in the SAML Redirect Binding implementation of Keycloak, an open-source identity and access management solution. The issue occurs because the custom DEFLATE compression and decompression helpers fail to release native zlib memory after use. An unauthenticated attacker can exploit this by sending repeated malformed SAML requests, leading to native memory exhaustion and a denial of service.

A flaw was found in the SAML Redirect Binding implementation of Keycloak, an open-source identity and access management solution. The issue occurs because the custom DEFLATE compression and decompression helpers fail to release native zlib memory after use. An unauthenticated attacker can exploit this by sending repeated malformed SAML requests, leading to native memory exhaustion and a denial of service.

keycloak-services: keycloak-services: Privilege escalation via impersonation role allows takeover of realm administrator accounts keycloak-services: keycloak-services: SAML Redirect DEFLATE helpers leak native zlib state keycloak-services: keycloak-services: Broker-originated username collision causes account lockout keycloak-services: keycloak-services: Incomplete fix for arbitrary filesystem path probing via keystore parameters io.netty/netty-handler: Netty: TLS hostname verification bypass via OpenSSL client path misconfiguration keycloak-services: keycloak-services: Incomplete fix for CVE-2026-15573 allows policy enforcer bypass via percent-encoded URI segments keycloak-services: keycloak-services: unauthenticated DoS via unbounded locale caching

Ein Angreifer kann mehrere Schwachstellen in Keycloak ausnutzen, um Sicherheitsvorkehrungen zu umgehen, um seine Privilegien zu erhöhen, um einen Denial of Service Angriff durchzuführen und um Informationen offenzulegen.