CVE-2026-72036
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
In the Linux kernel network scheduler sch_multiq, a vulnerability exists due to direct dequeue call instead of using peek and qdisc_dequeue_peeked. When the child is non-work-conserving, direct dequeue can lead to qlen/backlog desync and potential kernel panic.
Risk Assessment
This could lead to kernel panic during normal network traffic, especially in configurations with qfq and tbf.
Recommendation
Apply a kernel update containing the fix that uses qdisc_dequeue_peeked() instead of direct dequeue call.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_multiq: Replace direct dequeue call with peek and qdisc_dequeue_peeked multiq_dequeue() takes a packet from a band's child with a direct ->dequeue() call after multiq_peek() peeked it. When the child is non-work-conserving the peek stashes the skb in the child's gso_skb, so the direct dequeue returns a different skb and orphans the stash, desyncing the child's qlen/backlog. With a qfq child reached through a peeking parent (e.g. tbf) this re-enters the child on an emptied list and dereferences NULL, panicking the kernel from softirq on ordinary egress. Take the packet through qdisc_dequeue_peeked(), as sch_prio already does and as sch_red and sch_sfb were just fixed to do. The helper is a no-op when the child has no stash, so a work-conserving child is unaffected.