# CVE-2026-93574: Io.netty/netty-codec-http: netty: http request smuggling via post-digit whitespace in chunk-size parsing Status: published. Published: 2026-09-18. Updated: 2026-11-06. A flaw was found in Netty's `netty-codec-http` component. A remote attacker could exploit this vulnerability by sending a specially crafted HTTP/1.1 chunk-size token that includes post-digit whitespace. This incorrect parsing of the chunk size can lead to HTTP request smuggling. This allows an attacker to bypass security controls or access unauthorized resources in proxy/backend deployments. ## Remediation - workaround: See https://github.com/netty/netty/security/advisories/GHSA-j4mg-hqgv-34qc for fixed versions and remediation guidance. (source: CNA: redhat) ## Affected products and versions - Red Hat / Red Hat Build of Debezium 3.6 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat build of Keycloak 26.4 (keycloak-rhel9-container): ≥ 26.4-29; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat build of Keycloak 26.4 (keycloak-rhel9-operator-bundle-container): ≥ 26.4.17-2; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat build of Keycloak 26.4 (keycloak-rhel9-operator-container): ≥ 26.4-30; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat build of Keycloak 26.6.8 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat build of Quarkus 3.27.5.SP2 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat build of Quarkus 3.33.3.SP2 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat AMQ Broker 7 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat AMQ Clients (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat build of Apache Camel 4 for Quarkus 3 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat build of Apache Camel for Spring Boot 4 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat build of Apicurio Registry 3 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Data Grid 8 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Fuse 7 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat JBoss Enterprise Application Platform 7 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat JBoss Enterprise Application Platform 8 (netty-codec-http): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Single Sign-On 7 (netty-codec-http): Version range not reported. Source: CNA: redhat ## Severity and prioritization - CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L; source: CNA: redhat - CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L; source: NVD: secalert@redhat.com - CISA KEV: No listing in collected sources - EPSS: 1.35% as of 2026-11-05; percentile 71.71% - SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP - Weaknesses: CWE-444 ## Exploit evidence No exploit evidence in collected sources. This is not proof of no exploitation. ## References - https://access.redhat.com/errata/RHSA-2026:69440 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/errata/RHSA-2026:69470 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/errata/RHSA-2026:83612 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/errata/RHSA-2026:95760 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/errata/RHSA-2026:95761 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/security/cve/CVE-2026-93574 (CNA: redhat; vdb-entry, x_refsource_REDHAT) - https://bugzilla.redhat.com/show_bug.cgi?id=2536966 (CNA: redhat; issue-tracking, x_refsource_REDHAT) - https://access.redhat.com/errata/RHSA-2026:69440 (secalert@redhat.com) - https://access.redhat.com/errata/RHSA-2026:69470 (secalert@redhat.com) - https://access.redhat.com/errata/RHSA-2026:83612 (secalert@redhat.com) - https://access.redhat.com/errata/RHSA-2026:95760 (secalert@redhat.com) - https://access.redhat.com/errata/RHSA-2026:95761 (secalert@redhat.com) - https://access.redhat.com/security/cve/CVE-2026-93574 (secalert@redhat.com) - https://bugzilla.redhat.com/show_bug.cgi?id=2536966 (secalert@redhat.com) ## Provenance - CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-93574; retrieved 2026-11-06; source updated 2026-11-06 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93574; retrieved 2026-11-06; source updated 2026-11-06 - FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-93574; retrieved 2026-11-06; source updated Not reported Revision: 4cb00923c001b6ed973e27d65410df423b137e7a6b1d760fb4c0a39e05ecc274 Canonical: https://y2.dev/cve/CVE-2026-93574 ## Agent and API access Public CVE pages, Markdown, and JSON are free to read without an account or API key. - Public catalog: https://y2.dev/cve/index.json. 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