{"id":"CVE-2025-38733","title":"kernel: Linux kernel: Denial of Service due to incorrect lowcore memory mapping (CVE-2025-38733)","summary":"A flaw was found in the Linux kernel. Due to an incorrect identity mapping of the lowcore, a critical memory region, NULL pointer accesses may succeed instead of causing an exception. This vulnerability allows a local attacker to cause a D…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":"CWE-476","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 9"],"published":"2025-09-05","updated":"2026-10-16","sourceUpdated":"2026-10-16T23:23:59+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-38733.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-38733.json"},{"url":"https://access.redhat.com/security/cve/CVE-2025-38733"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2393520"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-38733"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38733"},{"url":"https://lore.kernel.org/linux-cve-announce/2025090543-CVE-2025-38733-65a1@gregkh/T"},{"url":"https://git.kernel.org/stable/c/30bf5728bb217a6d1ba73f44094c9b9c6bc9a567"},{"url":"https://git.kernel.org/stable/c/1d7864acd497cb468a998d44631f84896f885e85"},{"url":"https://git.kernel.org/stable/c/93f616ff870a1fb7e84d472cad0af651b18f9f87"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00166,"epssPercentile":0.05764,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-15T21:53:03.211075Z"},"scores":{"vendor":5.5,"cna":7.8},"ingestedAt":"2026-10-15T22:48:25.519Z","slug":"CVE-2025-38733","body":"## Overview\n\nA flaw was found in the Linux kernel. Due to an incorrect identity mapping of the lowcore, a critical memory region, NULL pointer accesses may succeed instead of causing an exception. This vulnerability allows a local attacker to cause a Denial of Service (DoS) by triggering a system crash.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-38733.json)\n\n**kernel: Linux kernel: Denial of Service due to incorrect lowcore memory mapping** — rated Low by Red Hat. Released 2025-09-05, updated 2026-10-16.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n\nNot affected:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n\n## Remediation\n\nFix deferred\n\nWorkarounds / mitigations:\n\n- 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.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":223568,"id":"CVE-2025-38733","ts":1792238317967,"field":"cvss","old":"7.8","new":"5.5"},{"seq":223567,"id":"CVE-2025-38733","ts":1792238317967,"field":"severity","old":"high","new":"medium"}]}