{"id":"CVE-2026-89743","title":"misc: nsm: bound the device-reported response length","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmisc: nsm: bound the device-reported response length\n\nnsm_sendrecv_msg_locked() stores the virtqueue used-ring length reported\nby the NSM device into msg->resp.len with…","severity":"high","cvss":7.7,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","cvssSource":"cna","cwe":["CWE-125"],"vendor":"Linux","product":"Linux","affected":["Linux >= b9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 339f19b9a6171289b0e797deb8bda80b9a1fcc30","Linux >= b9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 29e634a18957acda11383a15ab98a91c4ae9e294","Linux >= b9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 2aa0fb9c96f894a9c179a48e7522ea6705800adf","Linux >= b9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 808e530654a5354e6df78863a5d61e4d44e67235","Linux 6.8"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:51:57.186Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89743","references":[{"url":"https://git.kernel.org/stable/c/339f19b9a6171289b0e797deb8bda80b9a1fcc30"},{"url":"https://git.kernel.org/stable/c/29e634a18957acda11383a15ab98a91c4ae9e294"},{"url":"https://git.kernel.org/stable/c/2aa0fb9c96f894a9c179a48e7522ea6705800adf"},{"url":"https://git.kernel.org/stable/c/808e530654a5354e6df78863a5d61e4d44e67235"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89743.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89743"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532206"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89743"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89743"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89743.mbox"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00142,"epssPercentile":0.03451,"scores":{"cna":7.7,"vendor":5.5},"ingestedAt":"2026-09-14T15:23:07.472Z","slug":"CVE-2026-89743","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmisc: nsm: bound the device-reported response length\n\nnsm_sendrecv_msg_locked() stores the virtqueue used-ring length reported\nby the NSM device into msg->resp.len without bounding it to the response\nbuffer. A malicious or buggy backend can report a length larger than the\nresponse buffer; parse_resp_raw() then copies that many bytes out of the\nfixed buffer to user space, disclosing adjacent kernel heap (an\nout-of-bounds read). The request path already floors its length in\nfill_req_raw(); the response path lacks the symmetric check.\n\nClamp the stored length to the size of the response buffer. Well-behaved\ndevices report no more than the posted buffer size, so conforming traffic\nis unaffected.\n\n## Affected\n\n- `Linux >= b9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 339f19b9a6171289b0e797deb8bda80b9a1fcc30`\n- `Linux >= b9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 29e634a18957acda11383a15ab98a91c4ae9e294`\n- `Linux >= b9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 2aa0fb9c96f894a9c179a48e7522ea6705800adf`\n- `Linux >= b9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 808e530654a5354e6df78863a5d61e4d44e67235`\n- `Linux 6.8`\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 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89743.json)","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":42.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":224582,"id":"CVE-2026-89743","ts":1792401419601,"field":"cvss","old":"5.5","new":"7.7"},{"seq":224581,"id":"CVE-2026-89743","ts":1792401419601,"field":"severity","old":"medium","new":"high"},{"seq":208949,"id":"CVE-2026-89743","ts":1790062298145,"field":"cvss","old":"6.3","new":"5.5"},{"seq":203035,"id":"CVE-2026-89743","ts":1789403733442,"field":"cvss","old":"7.7","new":"6.3"},{"seq":203034,"id":"CVE-2026-89743","ts":1789403733442,"field":"severity","old":"high","new":"medium"},{"seq":197680,"id":"CVE-2026-89743","ts":1789384318365,"field":"cvss","old":"6.3","new":"7.7"},{"seq":197679,"id":"CVE-2026-89743","ts":1789384318365,"field":"severity","old":"medium","new":"high"},{"seq":183833,"id":"CVE-2026-89743","ts":1789356677598,"field":"cvss","old":"7.7","new":"6.3"},{"seq":183832,"id":"CVE-2026-89743","ts":1789356677598,"field":"severity","old":"high","new":"medium"},{"seq":153628,"id":"CVE-2026-89743","ts":1789285351619,"field":"cvss","old":null,"new":"7.7"},{"seq":153627,"id":"CVE-2026-89743","ts":1789285351619,"field":"severity","old":"none","new":"high"},{"seq":147546,"id":"CVE-2026-89743","ts":1789270211332,"field":"cvss","old":null,"new":"6.3"},{"seq":147545,"id":"CVE-2026-89743","ts":1789270211332,"field":"severity","old":"none","new":"medium"},{"seq":109294,"id":"CVE-2026-89743","ts":1789183731315,"field":"cvss","old":null,"new":"6.3"},{"seq":109293,"id":"CVE-2026-89743","ts":1789183731315,"field":"severity","old":"none","new":"medium"}]}