{"id":"CVE-2026-18212","state":"PUBLISHED","title":"Keycloak-services: keycloak-services: saml redirect deflate helpers leak native zlib state","description":"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.","publishedAt":"2026-09-16T14:54:15.431Z","updatedAt":"2026-09-16T18:35:27.170Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"redhat"},"assigner":"redhat","products":["Red Hat Red Hat build of Keycloak 26.4","Red Hat Red Hat build of Keycloak 26.4.16","Red Hat Red Hat build of Keycloak 26.6","Red Hat Red Hat build of Keycloak 26.6.7","Red Hat Red Hat Data Grid 8","Red Hat Red Hat JBoss Enterprise Application Platform Expansion Pack","Red Hat Red Hat Single Sign-On 7"],"affected":[{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.4","packageName":"rhbk/keycloak-operator-bundle","defaultStatus":"affected","versions":[{"version":"26.4.16-2","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.4::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.4","packageName":"rhbk/keycloak-rhel9","defaultStatus":"affected","versions":[{"version":"26.4-26","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.4::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.4","packageName":"rhbk/keycloak-rhel9-operator","defaultStatus":"affected","versions":[{"version":"26.4-26","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.4::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.4.16","packageName":"keycloak-services","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:build_keycloak:26.4::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.4.16","packageName":"rhbk-openshift-rhel9/rhbk-openshift-rhel9","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:build_keycloak:26.4::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6","packageName":"rhbk/keycloak-operator-bundle","defaultStatus":"affected","versions":[{"version":"26.6.7-3","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6","packageName":"rhbk/keycloak-rhel9","defaultStatus":"affected","versions":[{"version":"26.6-20","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6","packageName":"rhbk/keycloak-rhel9-operator","defaultStatus":"affected","versions":[{"version":"26.6-20","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6.7","packageName":"keycloak-services","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6.7","packageName":"rhbk-keycloak-rhel9/rhbk-keycloak-rhel9","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6.7","packageName":"rhbk-openshift-rhel9/rhbk-openshift-rhel9","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat Data Grid 8","packageName":"keycloak-services","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:jboss_data_grid:8"]},{"vendor":"Red Hat","product":"Red Hat JBoss Enterprise Application Platform Expansion Pack","packageName":"keycloak-services","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/jbossnetwork/restricted/listSoftware.html","cpes":["cpe:/a:redhat:jbosseapxp"]},{"vendor":"Red Hat","product":"Red Hat Single Sign-On 7","packageName":"keycloak-services","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:red_hat_single_sign_on:7"]}],"references":["https://access.redhat.com/errata/RHSA-2026:68276","https://access.redhat.com/errata/RHSA-2026:68277","https://access.redhat.com/errata/RHSA-2026:68278","https://access.redhat.com/errata/RHSA-2026:68280","https://access.redhat.com/security/cve/CVE-2026-18212","https://bugzilla.redhat.com/show_bug.cgi?id=2508307"],"weaknesses":["CWE-401"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/18xxx/CVE-2026-18212.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-18212","state":"PUBLISHED","datePublished":"2026-09-16T14:54:15.431Z","dateUpdated":"2026-09-16T18:35:27.170Z","assignerShortName":"redhat","assignerOrgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","dateReserved":"2026-07-29T08:31:24.186Z"},"containers":{"cna":{"title":"Keycloak-services: keycloak-services: saml redirect deflate helpers leak native zlib state","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.4","packageName":"rhbk/keycloak-operator-bundle","defaultStatus":"affected","versions":[{"version":"26.4.16-2","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.4::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.4","packageName":"rhbk/keycloak-rhel9","defaultStatus":"affected","versions":[{"version":"26.4-26","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.4::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.4","packageName":"rhbk/keycloak-rhel9-operator","defaultStatus":"affected","versions":[{"version":"26.4-26","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.4::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.4.16","packageName":"keycloak-services","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:build_keycloak:26.4::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.4.16","packageName":"rhbk-openshift-rhel9/rhbk-openshift-rhel9","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:build_keycloak:26.4::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6","packageName":"rhbk/keycloak-operator-bundle","defaultStatus":"affected","versions":[{"version":"26.6.7-3","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6","packageName":"rhbk/keycloak-rhel9","defaultStatus":"affected","versions":[{"version":"26.6-20","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6","packageName":"rhbk/keycloak-rhel9-operator","defaultStatus":"affected","versions":[{"version":"26.6-20","status":"unaffected","lessThan":"*","versionType":"rpm"}],"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6.7","packageName":"keycloak-services","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6.7","packageName":"rhbk-keycloak-rhel9/rhbk-keycloak-rhel9","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat build of Keycloak 26.6.7","packageName":"rhbk-openshift-rhel9/rhbk-openshift-rhel9","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:build_keycloak:26.6::el9"]},{"vendor":"Red Hat","product":"Red Hat Data Grid 8","packageName":"keycloak-services","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:jboss_data_grid:8"]},{"vendor":"Red Hat","product":"Red Hat JBoss Enterprise Application Platform Expansion Pack","packageName":"keycloak-services","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/jbossnetwork/restricted/listSoftware.html","cpes":["cpe:/a:redhat:jbosseapxp"]},{"vendor":"Red Hat","product":"Red Hat Single Sign-On 7","packageName":"keycloak-services","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:red_hat_single_sign_on:7"]}],"references":[{"url":"https://access.redhat.com/errata/RHSA-2026:68276","name":"RHSA-2026:68276","tags":["vendor-advisory","x_refsource_REDHAT"]},{"url":"https://access.redhat.com/errata/RHSA-2026:68277","name":"RHSA-2026:68277","tags":["vendor-advisory","x_refsource_REDHAT"]},{"url":"https://access.redhat.com/errata/RHSA-2026:68278","name":"RHSA-2026:68278","tags":["vendor-advisory","x_refsource_REDHAT"]},{"url":"https://access.redhat.com/errata/RHSA-2026:68280","name":"RHSA-2026:68280","tags":["vendor-advisory","x_refsource_REDHAT"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-18212","tags":["vdb-entry","x_refsource_REDHAT"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2508307","name":"RHBZ#2508307","tags":["issue-tracking","x_refsource_REDHAT"]}],"metrics":[{"other":{"content":{"value":"Important","namespace":"https://access.redhat.com/security/updates/classification/"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-401","description":"Missing Release of Memory after Effective Lifetime","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"redhat","orgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","dateUpdated":"2026-09-16T18:09:14.297Z"},"datePublic":"2026-09-16T12:57:23.000Z","x_redhatCweChain":"CWE-401: Missing Release of Memory after Effective Lifetime","workarounds":[{"lang":"en","value":"Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."}],"timeline":[{"lang":"en","time":"2026-07-28T12:27:32.000Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-09-16T12:57:23.000Z","value":"Made public."}],"credits":[{"lang":"en","value":"Red Hat would like to thank Paul Bottinelli (Trail of Bits in collaboration with OpenAI) for reporting this issue."}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-16T18:25:11.882582Z","id":"CVE-2026-18212","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-16T18:35:27.170Z"}}]}}}