{"id":"CVE-2026-64524","title":"kernel: drm/hyperv: validate resolution_count and fix WIN8 fallback (CVE-2026-64524)","summary":"A flaw was found in the Linux kernel's `drm/hyperv` component. A malicious Hyper-V guest could exploit an out-of-bounds memory access vulnerability by sending a crafted resolution response. This could potentially lead to information disclo…","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-125","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 9"],"published":"2026-07-25","updated":"2026-10-23","sourceUpdated":"2026-10-23T11:18:30+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64524.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64524.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-64524"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2507029"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64524"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64524"},{"url":"https://lore.kernel.org/linux-cve-announce/2026072533-CVE-2026-64524-0002@gregkh/T"},{"url":"https://git.kernel.org/stable/c/96f7de3172d4aa878b7f87173b2b3507c350fcd6"},{"url":"https://git.kernel.org/stable/c/bc573752f3dac0d1ab8df7078c1851bc76717653"},{"url":"https://git.kernel.org/stable/c/1fb565b77b8f44afabb02de6310065f109d89e94"},{"url":"https://git.kernel.org/stable/c/a321c908f2eeea01539668eb270d074d9b88e490"},{"url":"https://git.kernel.org/stable/c/9c698b2c43c2667c34f5336bf46ad5786216ac2a"},{"url":"https://git.kernel.org/stable/c/8a114b25b5521eae451b13bce98ae978624962e5"},{"url":"https://git.kernel.org/stable/c/13d33b9ef67066c77c84273fac5a1d3fde3533d1"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00142,"epssPercentile":0.03516,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-16T15:41:39.558295Z"},"scores":{"vendor":5.5,"cna":7.7},"ingestedAt":"2026-10-16T17:24:46.825Z","slug":"CVE-2026-64524","body":"## Overview\n\nA flaw was found in the Linux kernel's `drm/hyperv` component. A malicious Hyper-V guest could exploit an out-of-bounds memory access vulnerability by sending a crafted resolution response. This could potentially lead to information disclosure or a denial of service. Additionally, an issue with the resolution probe fallback mechanism could prevent display functionality from initializing correctly, resulting in a denial of service.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · 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 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64524.json)\n\n**kernel: drm/hyperv: validate resolution_count and fix WIN8 fallback** — rated Moderate by Red Hat. Released 2026-07-25, updated 2026-10-23.\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","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":228080,"id":"CVE-2026-64524","ts":1792758072564,"field":"cvss","old":"7.7","new":"5.5"},{"seq":228079,"id":"CVE-2026-64524","ts":1792758072564,"field":"severity","old":"high","new":"medium"}]}