Red Hat Product Errata RHSA-2026:23259 - Security Advisory Issued: 2026-06-04 Updated: 2026-06-04 RHSA-2026:23259 - Security Advisory Overview Updated Packages Synopsis Important: kernel-rt security update Type/Severity Security Advisory: Important Red Hat Lightspeed patch analysis Identify and remediate systems affected by this advisory. View affected systems Topic An update for kernel-rt is now available for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section. Description The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements. Security Fix(es): kernel: Linux kernel: smb: client: reject userspace cifs.spnego descriptions (CVE-2026-46243) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Solution For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect. Affected Products Red Hat Enterprise Linux for Real Time 8 x86_64 Red Hat Enterprise Linux for Real Time for NFV 8 x86_64 Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 8.10 x86_64 Fixes BZ - 2481486 - CVE-2026-46243 kernel: Linux kernel: smb: client: reject userspace cifs.spnego descriptions CVEs CVE-2026-46243 References https://access.redhat.com/security/updates/classification/#important Note: More recent versions of these packages may be available. Click a package name for more details. Red Hat Enterprise Linux for Real Time 8 SRPM kernel-rt-4.18.0-553.129.1.rt7.470.el8_10.src.rpm SHA-256: dd225af1e4e74800c60ad05b34ecba08d7bf6f606e35418af2bf0652e20b3399 x86_64 kernel-rt-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: d2e3d38885e6e0c06dae6e42f6439c190bcda3568d520820ccf3a342a6f4aae9 kernel-rt-core-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 5944cc4b0a72404ce26169b329763af63cdc811a2b73feae5f7a81826f4ca288 kernel-rt-debug-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 3f3335860ea22a335b1e1318916907e5b02350705a44d2c576f465d3783b878c kernel-rt-debug-core-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: d07cd3bc73e92fd0959c3ccb8b73a30a4a1a4000f361d635428238da7b167aa6 kernel-rt-debug-debuginfo-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 8f4092e0d8b6c98f6a6a6cc3f5ee0f68ed7f7ca60199db729febcb0660acdf02 kernel-rt-debug-devel-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: b593b5ddb0f5f382c00c64ebcd0daffdb8afd13b156d228f19dc3f8cd8938a11 kernel-rt-debug-modules-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 9951b2871b28354034a9cf5933768c550d445d65dc1e16117cea42753a022fd7 kernel-rt-debug-modules-extra-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 393e0b1fa58a994c6e336377f6696a80b546dfe4d01ae1948c62220fad21b8b6 kernel-rt-debuginfo-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 3bdd93b5b7348a47a65877bdea7b4d2547d6e1d4df2900fdca809bef8dc1f38c kernel-rt-debuginfo-common-x86_64-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 6ed8ba7793404d1babcb34809d25d15125a827db8b102cac4b197bf1f78fbf49 kernel-rt-devel-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: e1c5c27bb6d8e5db9870cb9927fb45dddcd60282dd60ce1c42fcdcf17a741c74 kernel-rt-modules-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 89e57467949dd02536ede85d25c94d613dc3478545de5069aa8e7183b20df98e kernel-rt-modules-extra-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 577e003ce45e72e8656c9926cf55c025d76a94841d6ac1c260aea04b459c90d0 Red Hat Enterprise Linux for Real Time for NFV 8 SRPM kernel-rt-4.18.0-553.129.1.rt7.470.el8_10.src.rpm SHA-256: dd225af1e4e74800c60ad05b34ecba08d7bf6f606e35418af2bf0652e20b3399 x86_64 kernel-rt-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: d2e3d38885e6e0c06dae6e42f6439c190bcda3568d520820ccf3a342a6f4aae9 kernel-rt-core-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 5944cc4b0a72404ce26169b329763af63cdc811a2b73feae5f7a81826f4ca288 kernel-rt-debug-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 3f3335860ea22a335b1e1318916907e5b02350705a44d2c576f465d3783b878c kernel-rt-debug-core-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: d07cd3bc73e92fd0959c3ccb8b73a30a4a1a4000f361d635428238da7b167aa6 kernel-rt-debug-debuginfo-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 8f4092e0d8b6c98f6a6a6cc3f5ee0f68ed7f7ca60199db729febcb0660acdf02 kernel-rt-debug-devel-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: b593b5ddb0f5f382c00c64ebcd0daffdb8afd13b156d228f19dc3f8cd8938a11 kernel-rt-debug-kvm-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 0142814a05763db5721233e624a2eaf669e946df751b010f1662f8cad8d00784 kernel-rt-debug-modules-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 9951b2871b28354034a9cf5933768c550d445d65dc1e16117cea42753a022fd7 kernel-rt-debug-modules-extra-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 393e0b1fa58a994c6e336377f6696a80b546dfe4d01ae1948c62220fad21b8b6 kernel-rt-debuginfo-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 3bdd93b5b7348a47a65877bdea7b4d2547d6e1d4df2900fdca809bef8dc1f38c kernel-rt-debuginfo-common-x86_64-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 6ed8ba7793404d1babcb34809d25d15125a827db8b102cac4b197bf1f78fbf49 kernel-rt-devel-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: e1c5c27bb6d8e5db9870cb9927fb45dddcd60282dd60ce1c42fcdcf17a741c74 kernel-rt-kvm-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 2bfaa400623161cddbbbeb0bf14e71d8141680820a50e8bb4ed33638a985ebca kernel-rt-modules-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 89e57467949dd02536ede85d25c94d613dc3478545de5069aa8e7183b20df98e kernel-rt-modules-extra-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 577e003ce45e72e8656c9926cf55c025d76a94841d6ac1c260aea04b459c90d0 Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 8.10 SRPM kernel-rt-4.18.0-553.129.1.rt7.470.el8_10.src.rpm SHA-256: dd225af1e4e74800c60ad05b34ecba08d7bf6f606e35418af2bf0652e20b3399 x86_64 kernel-rt-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: d2e3d38885e6e0c06dae6e42f6439c190bcda3568d520820ccf3a342a6f4aae9 kernel-rt-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: d2e3d38885e6e0c06dae6e42f6439c190bcda3568d520820ccf3a342a6f4aae9 kernel-rt-core-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 5944cc4b0a72404ce26169b329763af63cdc811a2b73feae5f7a81826f4ca288 kernel-rt-core-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 5944cc4b0a72404ce26169b329763af63cdc811a2b73feae5f7a81826f4ca288 kernel-rt-debug-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 3f3335860ea22a335b1e1318916907e5b02350705a44d2c576f465d3783b878c kernel-rt-debug-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 3f3335860ea22a335b1e1318916907e5b02350705a44d2c576f465d3783b878c kernel-rt-debug-core-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: d07cd3bc73e92fd0959c3ccb8b73a30a4a1a4000f361d635428238da7b167aa6 kernel-rt-debug-core-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: d07cd3bc73e92fd0959c3ccb8b73a30a4a1a4000f361d635428238da7b167aa6 kernel-rt-debug-debuginfo-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 8f4092e0d8b6c98f6a6a6cc3f5ee0f68ed7f7ca60199db729febcb0660acdf02 kernel-rt-debug-debuginfo-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 8f4092e0d8b6c98f6a6a6cc3f5ee0f68ed7f7ca60199db729febcb0660acdf02 kernel-rt-debug-devel-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: b593b5ddb0f5f382c00c64ebcd0daffdb8afd13b156d228f19dc3f8cd8938a11 kernel-rt-debug-devel-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: b593b5ddb0f5f382c00c64ebcd0daffdb8afd13b156d228f19dc3f8cd8938a11 kernel-rt-debug-kvm-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 0142814a05763db5721233e624a2eaf669e946df751b010f1662f8cad8d00784 kernel-rt-debug-modules-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 9951b2871b28354034a9cf5933768c550d445d65dc1e16117cea42753a022fd7 kernel-rt-debug-modules-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 9951b2871b28354034a9cf5933768c550d445d65dc1e16117cea42753a022fd7 kernel-rt-debug-modules-extra-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 393e0b1fa58a994c6e336377f6696a80b546dfe4d01ae1948c62220fad21b8b6 kernel-rt-debug-modules-extra-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 393e0b1fa58a994c6e336377f6696a80b546dfe4d01ae1948c62220fad21b8b6 kernel-rt-debuginfo-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 3bdd93b5b7348a47a65877bdea7b4d2547d6e1d4df2900fdca809bef8dc1f38c kernel-rt-debuginfo-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 3bdd93b5b7348a47a65877bdea7b4d2547d6e1d4df2900fdca809bef8dc1f38c kernel-rt-debuginfo-common-x86_64-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 6ed8ba7793404d1babcb34809d25d15125a827db8b102cac4b197bf1f78fbf49 kernel-rt-debuginfo-common-x86_64-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 6ed8ba7793404d1babcb34809d25d15125a827db8b102cac4b197bf1f78fbf49 kernel-rt-devel-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: e1c5c27bb6d8e5db9870cb9927fb45dddcd60282dd60ce1c42fcdcf17a741c74 kernel-rt-devel-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: e1c5c27bb6d8e5db9870cb9927fb45dddcd60282dd60ce1c42fcdcf17a741c74 kernel-rt-kvm-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 2bfaa400623161cddbbbeb0bf14e71d8141680820a50e8bb4ed33638a985ebca kernel-rt-modules-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 89e57467949dd02536ede85d25c94d613dc3478545de5069aa8e7183b20df98e kernel-rt-modules-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 89e57467949dd02536ede85d25c94d613dc3478545de5069aa8e7183b20df98e kernel-rt-modules-extra-4.18.0-553.129.1.rt7.470.el8_10.x86_64.rpm SHA-256: 577e003ce45e72e8656c9926cf55c0
A vulnerability (CVE-2026-46243, CVSS 7.8 HIGH) in the Linux kernel's SMB client allows userspace to pass malicious cifs.spnego descriptions, which the kernel must now reject. This security update is rated Important for the kernel-rt packages in Red Hat Enterprise Linux 8 for Real Time and related variants. The fix is provided in kernel-rt package version 4.18.0-553.129.1.rt7.470.el8_10, and a system reboot is required for the update to take effect.