{"id":"CVE-2026-89604","title":"kernel: efivarfs: Rate limit statfs() handler (CVE-2026-89604)","summary":"A flaw was found in the Linux kernel's efivarfs component. An unprivileged local user can exploit this by repeatedly calling the `statfs()` handler on the `efivarfs` mount point. This action triggers a flood of calls to the `QueryVariableI…","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-770","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-16","sourceUpdated":"2026-09-16T07:13:51+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89604.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89604.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89604"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532362"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89604"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89604"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89604.mbox"},{"url":"https://git.kernel.org/stable/c/0dbc2e94b81df5a1264068b6ed3605c654b8afcb"},{"url":"https://git.kernel.org/stable/c/8953bdd1b9c0e748d5408d3d0b8e7aeee5c9cd41"},{"url":"https://git.kernel.org/stable/c/92895a14329cc9533e2a74a265214f690ba3851a"},{"url":"https://git.kernel.org/stable/c/b2326338dc683e8c1067c0cbf7a47986c4190902"},{"url":"https://git.kernel.org/stable/c/97d71ebee48cd1b29091762b3e5cca4f815dd84c"},{"url":"https://git.kernel.org/stable/c/3cd611c9f1dbcc116c8af5112e3c1783c8cde2ae"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00205,"epssPercentile":0.10894,"ingestedAt":"2026-09-14T15:23:07.451Z","slug":"CVE-2026-89604","body":"## Overview\n\nA flaw was found in the Linux kernel's efivarfs component. An unprivileged local user can exploit this by repeatedly calling the `statfs()` handler on the `efivarfs` mount point. This action triggers a flood of calls to the `QueryVariableInfo()` runtime service, which is particularly costly on x86 systems. The excessive calls can lead to significant performance degradation, potentially resulting in a Denial of Service (DoS).\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89604.json)\n\n**kernel: efivarfs: Rate limit statfs() handler** — rated Low by Red Hat. Released 2026-09-11, updated 2026-09-16.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\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 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- Red Hat Enterprise Linux 8\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nFix deferred","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":205483,"id":"CVE-2026-89604","ts":1789576721773,"field":"cvss","old":"4.7","new":"5.5"},{"seq":203988,"id":"CVE-2026-89604","ts":1789490230936,"field":"cvss","old":null,"new":"4.7"},{"seq":203987,"id":"CVE-2026-89604","ts":1789490230936,"field":"severity","old":"none","new":"medium"},{"seq":147347,"id":"CVE-2026-89604","ts":1789270210550,"field":"cvss","old":null,"new":"4.7"},{"seq":147346,"id":"CVE-2026-89604","ts":1789270210550,"field":"severity","old":"none","new":"medium"},{"seq":109082,"id":"CVE-2026-89604","ts":1789183730236,"field":"cvss","old":null,"new":"4.7"},{"seq":109081,"id":"CVE-2026-89604","ts":1789183730236,"field":"severity","old":"none","new":"medium"}]}