{"cve":{"cve_id":"CVE-2023-4623","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.00287,"epss_percentile":0.20241,"epss_as_of":"2026-06-23","description":"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.","published_at":"2023-09-06T13:56:57.295000Z","last_modified_at":null,"cvss_v3_score":7.8,"cvss_v3_vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvss_v3_severity":"HIGH","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"none","ssvc_automatable":false,"ssvc_technical_impact":"total","cwes":["CWE-416"],"nvd_references":["https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f","https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f","https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html","http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html","https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-29T01:41:37.767234Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"L","value_label":"Local"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"L","value_label":"Low"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"kernel","product_name":"Kernel","version_start":"2.6.12","version_start_inclusive":true,"version_end":"6.6","version_end_inclusive":false,"cpe23_uri":"cve5:linux:kernel:2.6.12:6.6"}],"exploit_refs":[],"news":[],"references":[{"url":"https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f","source_type":"MISC","tags":["patch"]},{"url":"https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f","source_type":"MISC","tags":[]},{"url":"https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html","source_type":"MAILING_LIST","tags":["mailing-list"]},{"url":"http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html","source_type":"EXPLOIT","tags":["exploit","patch"]},{"url":"https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html","source_type":"MAILING_LIST","tags":["mailing-list"]}],"timeline":[{"type":"published","at":"2023-09-06T13:56:57.295000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:30:48.906316Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:30:48.906316Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:30:48.906316Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"ssvc_changed","at":"2026-06-29T01:41:37.767234Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T01:41:37.767234Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T01:41:37.767234Z","label":"SSVC decision revised","source":"vulnrichment"}]}