{"id":"CVE-2026-89765","title":"kernel: timers/itimer: Zero-init old itimerval before copy to userspace (CVE-2026-89765)","summary":"A flaw was found in the Linux kernel's `timers/itimer` component. On native sparc64 systems, the `struct __kernel_old_timeval` contains uninitialized padding bytes. When `put_itimerval()` copies this structure to userspace, these padding b…","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-201","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 8","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-21","sourceUpdated":"2026-09-21T18:32:05+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89765.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89765.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89765"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532295"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89765"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89765"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89765.mbox"},{"url":"https://git.kernel.org/stable/c/00ef529a5402f41eb1d227916437e237450719f9"},{"url":"https://git.kernel.org/stable/c/18c7d85864e554adc8fad1e8d2e9d2cb6c3911c8"},{"url":"https://git.kernel.org/stable/c/2bf5e8f7c9bf4ad3be343a9a6e3e50a34264d25e"},{"url":"https://git.kernel.org/stable/c/4c66719dd1e4023c5e3f7d050f1bbefec3dfbeb4"},{"url":"https://git.kernel.org/stable/c/6d4b937251386d9c6f968e7802f0cb16a8523772"},{"url":"https://git.kernel.org/stable/c/4ea70146ab9376092297eb8b622ef1792797f2cf"},{"url":"https://git.kernel.org/stable/c/a17b345daff46fec4af9f1ecbdf350208016dd15"},{"url":"https://git.kernel.org/stable/c/bdfda99c5763822a9a888e8af0ad7d9312ffcfe2"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00196,"epssPercentile":0.09583,"ingestedAt":"2026-09-14T15:23:07.448Z","slug":"CVE-2026-89765","body":"## Overview\n\nA flaw was found in the Linux kernel's `timers/itimer` component. On native sparc64 systems, the `struct __kernel_old_timeval` contains uninitialized padding bytes. When `put_itimerval()` copies this structure to userspace, these padding bytes can be exposed, leading to information disclosure. This vulnerability allows a local attacker to potentially read sensitive kernel memory.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, 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 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89765.json)\n\n**kernel: timers/itimer: Zero-init old itimerval before copy to userspace** — rated Low by Red Hat. Released 2026-09-11, updated 2026-09-21.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\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 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- Red Hat Enterprise Linux 7\n\n## Remediation\n\nFix deferred","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":208933,"id":"CVE-2026-89765","ts":1790062293806,"field":"cvss","old":"5.3","new":"5.5"},{"seq":204015,"id":"CVE-2026-89765","ts":1789490231054,"field":"cvss","old":null,"new":"5.3"},{"seq":204014,"id":"CVE-2026-89765","ts":1789490231054,"field":"severity","old":"none","new":"medium"},{"seq":147408,"id":"CVE-2026-89765","ts":1789270210793,"field":"cvss","old":null,"new":"5.3"},{"seq":147407,"id":"CVE-2026-89765","ts":1789270210793,"field":"severity","old":"none","new":"medium"},{"seq":109164,"id":"CVE-2026-89765","ts":1789183730562,"field":"cvss","old":null,"new":"5.3"},{"seq":109163,"id":"CVE-2026-89765","ts":1789183730562,"field":"severity","old":"none","new":"medium"}]}