{"id":"CVE-2026-97587","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf: RISC-V: store available counter mask as bitmap\n\nThe available-counter mask was a single unsigned long, but iteration\nuses RISCV_MAX_COUNTERS, which is 64","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf: RISC-V: store available counter mask as bitmap\n\nThe available-counter mask was a single unsigned long, but iteration\nuses RISCV_MAX_COUNTERS, which is 64. On RV32…","severity":"medium","vendor":"Linux","product":"Linux","affected":["Linux >= e9991434596f5373dfd75857b445eb92a9253c56 < 143668c424772979a45118dc9cc9c2c13a35f41d","Linux >= e9991434596f5373dfd75857b445eb92a9253c56 < 9bec7beaed074bcae4181fde9ff9dfbe4e7b0957","Linux >= e9991434596f5373dfd75857b445eb92a9253c56 < e5481db31f4654e9a1254d5d467d9b1ff2f8b1cb","Linux >= e9991434596f5373dfd75857b445eb92a9253c56 < 6809da6e9c08ccc9a09cb0a48c61471679274aaa","Linux 5.18"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T11:17:09.880","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97587","references":[{"url":"https://git.kernel.org/stable/c/143668c424772979a45118dc9cc9c2c13a35f41d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6809da6e9c08ccc9a09cb0a48c61471679274aaa","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9bec7beaed074bcae4181fde9ff9dfbe4e7b0957","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e5481db31f4654e9a1254d5d467d9b1ff2f8b1cb","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97587.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-97587"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541258"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97587"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97587"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97587.mbox"},{"url":"https://git.kernel.org/stable/c/5a1b6379eed5b13eac0228b605b0bed988e547e9"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ingestedAt":"2026-09-25T11:06:38.906Z","epss":0.00201,"epssPercentile":0.09838,"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"],"slug":"CVE-2026-97587","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nperf: RISC-V: store available counter mask as bitmap\n\nThe available-counter mask was a single unsigned long, but iteration\nuses RISCV_MAX_COUNTERS, which is 64. On RV32 that reads past the object.\nFilling with an unsigned-long bit at index 32 and above is also wrong.\n\nUse DECLARE_BITMAP and set_bit/bitmap helpers. Walk each bitmap word\ninto CFG_MATCH when checking events, when allocating an index, and when\nstopping all counters. Set the counter base to i times BITS_PER_LONG.\nShare the CFG_MATCH ecall through a small helper so the 32-bit argument\nsplit is not duplicated. On qemu-system-riscv32 the probe bitmap has bits\nabove XLEN set, so the first word alone is not enough.\n\n[pjw@kernel.org: updated to apply; fixed checkpatch.pl issues]\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 · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97587.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":224264,"id":"CVE-2026-97587","ts":1792325052767,"field":"cvss","old":null,"new":"5.5"},{"seq":224263,"id":"CVE-2026-97587","ts":1792325052767,"field":"severity","old":"none","new":"medium"}]}