{"id":"AZL-31697","summary":"CVE-2023-4623 affecting package kernel for versions less than 5.15.135.1-2","details":"A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation.\n\nIf a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free.\n\nWe recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.","modified":"2026-04-01T05:10:20.670846Z","published":"2023-09-06T14:15:12Z","upstream":["CVE-2023-4623"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-4623"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.135.1-2"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-31697.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}