{"id":"CVE-2023-31436","title":"qfq_change_class in net/sched/sch_qfq.c in the Linux kernel before 6.2.13 allows an out-of-bounds write because lmax can exceed QFQ_MIN_LMAX.","summary":"qfq_change_class in net/sched/sch_qfq.c in the Linux kernel before 6.2.13 allows an out-of-bounds write because lmax can exceed QFQ_MIN_LMAX.","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-787"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 3.7, < 4.14.314","linux_kernel >= 4.15, < 4.19.282","linux_kernel >= 4.20, < 5.4.242","linux_kernel >= 5.5.0, < 5.10.179","linux_kernel >= 5.11, < 5.15.109","linux_kernel >= 5.16, < 6.1.26","linux_kernel >= 6.2, < 6.2.13"],"patched":["linux_kernel 6.2.13"],"published":"2023-04-28","updated":"2026-10-14","sourceUpdated":"2026-10-14T23:17:18.727","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2023-31436","references":[{"url":"http://packetstormsecurity.com/files/173087/Kernel-Live-Patch-Security-Notice-LSN-0095-1.html","label":"cve@mitre.org"},{"url":"http://packetstormsecurity.com/files/173757/Kernel-Live-Patch-Security-Notice-LSN-0096-1.html","label":"cve@mitre.org"},{"url":"http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html","label":"cve@mitre.org"},{"url":"https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.2.13","label":"cve@mitre.org"},{"url":"https://github.com/torvalds/linux/commit/3037933448f60f9acb705997eae62013ecb81e0d","label":"cve@mitre.org"},{"url":"https://lists.debian.org/debian-lts-announce/2023/06/msg00008.html","label":"cve@mitre.org"},{"url":"https://security.netapp.com/advisory/ntap-20230609-0001/","label":"cve@mitre.org"},{"url":"https://www.debian.org/security/2023/dsa-5402","label":"cve@mitre.org"},{"url":"https://www.spinics.net/lists/stable-commits/msg294885.html","label":"cve@mitre.org"},{"url":"http://packetstormsecurity.com/files/173087/Kernel-Live-Patch-Security-Notice-LSN-0095-1.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://packetstormsecurity.com/files/173757/Kernel-Live-Patch-Security-Notice-LSN-0096-1.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.2.13","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/torvalds/linux/commit/3037933448f60f9acb705997eae62013ecb81e0d","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2023/06/msg00008.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20230609-0001/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2023/dsa-5402","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.spinics.net/lists/stable-commits/msg294885.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-794697.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-806742.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00598,"epssPercentile":0.48414,"ingestedAt":"2026-10-15T00:02:07.133Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2024-10-15T17:15:52.761316Z"},"slug":"CVE-2023-31436","body":"## Overview\n\nqfq_change_class in net/sched/sch_qfq.c in the Linux kernel before 6.2.13 allows an out-of-bounds write because lmax can exceed QFQ_MIN_LMAX.\n\n## Affected\n\n- `linux_kernel >= 3.7, < 4.14.314`\n- `linux_kernel >= 4.15, < 4.19.282`\n- `linux_kernel >= 4.20, < 5.4.242`\n- `linux_kernel >= 5.5.0, < 5.10.179`\n- `linux_kernel >= 5.11, < 5.15.109`\n- `linux_kernel >= 5.16, < 6.1.26`\n- `linux_kernel >= 6.2, < 6.2.13`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.2.13`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}