CVE-2026-18212: fallo de gravedad alta en Red Hat build of Keycloak 26.4
Keycloak-services: keycloak-services: saml redirect deflate helpers leak native zlib state
Publicada el
Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.
21Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 7.5epss 0.7%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Productos afectados
Red Hat · Red Hat build of Keycloak 26.4Red Hat · Red Hat build of Keycloak 26.4.16Red Hat · Red Hat build of Keycloak 26.6Red Hat · Red Hat build of Keycloak 26.6.7Red Hat · Red Hat Data Grid 8Red Hat · Red Hat JBoss Enterprise Application Platform Expansion PackRed Hat · Red Hat Single Sign-On 7CVEs relacionadas — Red Hat build of Keycloak 26.4
En el mismo producto, de las más peligrosas a las menos.
CVE-2026-18963CRITICALKeycloak-services: keycloak-services: unauthenticated account takeover via reset-credentials flow bypassEPSS 4.7%CVE-2026-93567HIGHIo.netty/netty-codec-http2: http/1 authority-form connect is translated to malformed http/2 connect with host-controlled :authorityEPSS 2.6%CVE-2026-93569HIGHIo.netty/netty-codec-http2: http/1 absolute-form host mismatch is translated to http/2 :authority, overriding the request-target authorityEPSS 2.2%CVE-2026-93574MEDIUMIo.netty/netty-codec-http: netty: http request smuggling via post-digit whitespace in chunk-size parsingEPSS 1.4%CVE-2026-93558HIGHIo.netty/netty-codec-http: netty: unbounded per-connection queue growth in websocketserverextensionhandler leads to denial of serviceEPSS 1.1%CVE-2026-93568HIGHIo.netty/netty-codec-http2: io.netty/netty-codec-http3: netty: http/2 and http/3 extended connect requests are downgraded as regular connect requestsEPSS 1.0%
Referencias
https://access.redhat.com/errata/RHSA-2026:68276https://access.redhat.com/errata/RHSA-2026:68277https://access.redhat.com/errata/RHSA-2026:68278https://access.redhat.com/errata/RHSA-2026:68280https://access.redhat.com/security/cve/CVE-2026-18212https://bugzilla.redhat.com/show_bug.cgi?id=2508307