{"id":"CVE-2026-98838","title":"kernel: vt: skip screen update for DEC alignment test on backgroup consoles (CVE-2026-98838)","summary":"A flaw was found in the Linux kernel's virtual terminal subsystem. When handling screen updates for background consoles, the kernel fails to properly verify that a console is active before redrawing it with modified font dimensions. A loca…","severity":"medium","cvss":4.4,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":"CWE-125","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 7","enterprise_linux 8","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-10-18","updated":"2026-10-23","sourceUpdated":"2026-10-23T21:49:00+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98838.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98838.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98838"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2555252"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98838"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98838"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98838.mbox"},{"url":"https://git.kernel.org/stable/c/2fc4e71aefab57c80ccc9775aad2af503fc90810"},{"url":"https://git.kernel.org/stable/c/985c000b046ca4ee11ee34ef85db500c569ef6e8"},{"url":"https://git.kernel.org/stable/c/ad06f7312d3f615dd466483ce81a9b9619166686"},{"url":"https://git.kernel.org/stable/c/0ee53081425a1a31ce15089012cd96b8353eb44e"},{"url":"https://git.kernel.org/stable/c/0928ed9bd7946baee911efa401088697836e3b1e"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00168,"epssPercentile":0.05973,"ingestedAt":"2026-10-18T16:47:32.468Z","slug":"CVE-2026-98838","body":"## Overview\n\nA flaw was found in the Linux kernel's virtual terminal subsystem. When handling screen updates for background consoles, the kernel fails to properly verify that a console is active before redrawing it with modified font dimensions. A local attacker can exploit this issue by altering font settings and issuing control sequences to an inactive console, triggering an out-of-bounds memory read against an unresized buffer. This can lead to a system crash, resulting in a Denial of Service (DoS), or potentially expose sensitive kernel memory.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, … · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98838.json)\n\n**kernel: vt: skip screen update for DEC alignment test on backgroup consoles** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-23.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNot affected:\n\n- Red Hat Enterprise Linux 6\n\n## Remediation\n\nFix deferred","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":24.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":228616,"id":"CVE-2026-98838","ts":1792844815654,"field":"cvss","old":null,"new":"4.4"},{"seq":228615,"id":"CVE-2026-98838","ts":1792844815654,"field":"severity","old":"none","new":"medium"}]}