{"id":"CVE-2026-98149","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix percpu map update indexing with sparse CPU IDs\n\nPer-CPU array, hash, and cgroup storage map updates without BPF_F_CPU\nor BPF_F_ALL_CPUS use a value buffer whos…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix percpu map update indexing with sparse CPU IDs\n\nPer-CPU array, hash, and cgroup storage map updates without BPF_F_CPU\nor BPF_F_ALL_CPUS use a value buffer whos…","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","cwe":["CWE-125"],"vendor":"Linux","product":"Linux","affected":["Linux >= 8eb76cb03f0f6c2bd7b15cf45dcffcd6bd07a360 < c16c62c91e5d6737a9fbb0a541b8b34610470a2b","Linux >= 8eb76cb03f0f6c2bd7b15cf45dcffcd6bd07a360 < 75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7","Linux 7.0"],"published":"2026-09-25","updated":"2026-09-30","sourceUpdated":"2026-09-30T14:10:59.253","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98149","references":[{"url":"https://git.kernel.org/stable/c/75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c16c62c91e5d6737a9fbb0a541b8b34610470a2b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98149.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98149"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541333"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98149"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98149"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98149.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00124,"epssPercentile":0.02153,"cvssSource":"vendor","ingestedAt":"2026-09-25T11:06:38.806Z","slug":"CVE-2026-98149","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix percpu map update indexing with sparse CPU IDs\n\nPer-CPU array, hash, and cgroup storage map updates without BPF_F_CPU\nor BPF_F_ALL_CPUS use a value buffer whose per-CPU slots are packed in\npossible-CPU order. The buffer is sized as:\n\n  round_up(value_size, 8) * num_possible_cpus()\n\nThe update paths iterate over possible CPUs, but use the logical CPU ID\nto calculate the source offset:\n\n  value + size * cpu\n\nThis only works when possible CPU IDs are contiguous starting at zero.\n\nFor example, with a possible CPU mask of 0,2-3, the buffer contains\nthree slots corresponding to CPUs 0, 2, and 3. CPU2 is therefore\nexpected to use slot 1 and CPU3 slot 2. Instead, the current code uses\nslots 2 and 3 respectively, causing incorrect per-CPU values and an\nout-of-bounds read from the update buffer for CPU3.\n\nThe corresponding lookup paths already use a dense offset while\niterating over possible CPUs. Do the same for the array, hash, and\ncgroup storage update paths, advancing the source offset once for each\npossible CPU. BPF_F_ALL_CPUS continues to use the same value for every\nCPU.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-09-28 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98149.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":212581,"id":"CVE-2026-98149","ts":1790668215111,"field":"cvss","old":null,"new":"5.5"},{"seq":212580,"id":"CVE-2026-98149","ts":1790668215111,"field":"severity","old":"none","new":"medium"}]}