{"cve":"CVE-2026-98011","nvd":{"published":"2026-09-25T11:17:29.427","modified":"2026-10-19T10:17:52.520","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: hhf: clamp quantum in change and init paths\n\nhhf_change() accepts any quantum from userspace, including 1. With a\ncrafted size table qdisc_pkt_len reaches ~2 GiB, so quantum=1 makes\nthe deficit-refill loop spin ~2^31 times under the qdisc lock\n(a soft lockup / denial of service).\n\nAdd max(256U, ...) in hhf_change() matching fq_codel_change(). Clamp\nhhf_init() to [256, 1<<20] matching the siblings, and remove the old\nfallback that only set quantum=256 on overflow.\n\nConditions to recreate the bug:\n  CONFIG_NET_SCH_HHF=y. Requires CAP_NET_ADMIN (namespace-local via\n  unshare -Urn suffices).\n\n  tc qdisc add dev dummy0 root hhf\n  tc qdisc change dev dummy0 root hhf quantum 1 stab data 32768 size_log 15 cell_log 0","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/0898c6f9fa9ce2632ae88bd0f34a878ccc6335af","https://git.kernel.org/stable/c/1113b674307ffddd402524bd1fd9d7d5629b705b","https://git.kernel.org/stable/c/2c6dd9fc86d446a03728c43f3b96d9ae29aa058f","https://git.kernel.org/stable/c/2e77947bbf6c166e76c038663832d0914418f761","https://git.kernel.org/stable/c/6570f326a6a96bedf3d1d1dab6acc9f8c29104ec"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-98011","score":0.00177,"percentile":0.07167,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}