CVE-2026-98009

high

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: ets: clamp quantum in parse and fallback paths ets_qdisc_change() falls back to psched_mtu() with no floor for bands without an explicit quantum. With a crafted size table qdisc_pkt_len reaches ~2 GiB, so a zero psched_mtu on a headerless device makes the deficit-refill loop spin under the qdisc lock. Move the floor into ets_quantum_parse() so explicitly configured quanta are also clamped to [256, 1<<20], not just the fallback path. Conditions to recreate the bug: CONFIG_NET_SCH_ETS=y. Requires CAP_NET_ADMIN (namespace-local via unshare -Urn suffices). tc qdisc add dev dummy0 root ets bands 3 strict 2 quanta 1 1

References

https://git.kernel.org/stable/c/de22c30ec5598aca8797f02082d2ee1358dfa3ff

https://git.kernel.org/stable/c/99ae477b892e203a37985ebc56f0063e072f7f4b

https://git.kernel.org/stable/c/8f80b113dea0bed3c1a31a4224b72775cd9ec52d

https://git.kernel.org/stable/c/8b8d782c3b96376217087767dcf662cd3d25f226

https://git.kernel.org/stable/c/4ef8664eafafc8db68a1d52601f17dc008a223b7

https://git.kernel.org/stable/c/440b66cc7b56ea38e9b878ae88da91992efaa4c4

https://git.kernel.org/stable/c/226d2702e74a570f5bfae6115b4706da4b94e5cf

https://git.kernel.org/stable/c/1c38487f46b243bfeefec0c0c86023a3904f2214

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-86662

Details

Source: Mitre, NVD

Published: 2026-09-25

Updated: 2026-10-03

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 8.4

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00176