{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.1.176-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.88-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.0.7-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked  When red qdisc has children (eg qfq qdisc) whose peek() callback is qdisc_peek_dequeued(), we could get a kernel panic. When the parent of such qdiscs (eg illustrated in patch #3 as tbf) wants to retrieve an skb from its child (red in this case), it will do the following:  1a. do a peek() - and when sensing there's an skb the child can offer, then      - the child in this case(red) calls its child's (qfq) peek.         qfq does the right thing and will return the gso_skb queue packet.         Note: if there wasnt a gso_skb entry then qfq will store it there.  1b. invoke a dequeue() on the child (red). And herein lies the problem.      - red will call the child's dequeue() which will essentially just        try to grab something of qfq's queue.  [   78.667668][  T363] KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f] [   78.667927][  T363] CPU: 1 UID: 0 PID: 363 Comm: ping Not tainted 7.1.0-rc1-00033-g46f74a3f7d57-dirty #790 PREEMPT(full) [   78.668263][  T363] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [   78.668486][  T363] RIP: 0010:qfq_dequeue+0x446/0xc90 [sch_qfq] [   78.668718][  T363] Code: 54 c0 e8 dd 90 00 f1 48 c7 c7 e0 03 54 c0 48 89 de e8 ce 90 00 f1 48 8d 7b 48 b8 ff ff 37 00 48 89 fa 48 c1 e0 2a 48 c1 ea 03 \u003c80\u003e 3c 02 00 74 05 e8 ef a1 e1 f1 48 8b 7b 48 48 8d 54 24 58 48 8d [   78.669312][  T363] RSP: 0018:ffff88810de573e0 EFLAGS: 00010216 [   78.669533][  T363] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 [   78.669790][  T363] RDX: 0000000000000009 RSI: 0000000000000004 RDI: 0000000000000048 [   78.670044][  T363] RBP: ffff888110dc4000 R08: ffffffffb1b0885a R09: fffffbfff6ba9078 [   78.670297][  T363] R10: 0000000000000003 R11: ffff888110e31c80 R12: 0000001880000000 [   78.670560][  T363] R13: ffff888110dc4150 R14: ffff888110dc42b8 R15: 0000000000000200 [   78.670814][  T363] FS:  00007f66a8f09c40(0000) GS:ffff888163428000(0000) knlGS:0000000000000000 [   78.671110][  T363] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [   78.671324][  T363] CR2: 000055db4c6a30a8 CR3: 000000010da67000 CR4: 0000000000750ef0 [   78.671585][  T363] PKRU: 55555554 [   78.671713][  T363] Call Trace: [   78.671843][  T363]  \u003cTASK\u003e [   78.671936][  T363]  ? __pfx_qfq_dequeue+0x10/0x10 [sch_qfq] [   78.672148][  T363]  ? __pfx__printk+0x10/0x10 [   78.672322][  T363]  ? srso_alias_return_thunk+0x5/0xfbef5 [   78.672496][  T363]  ? lockdep_hardirqs_on_prepare+0xa8/0x1a0 [   78.672706][  T363]  ? srso_alias_return_thunk+0x5/0xfbef5 [   78.672875][  T363]  ? trace_hardirqs_on+0x19/0x1a0 [   78.673047][  T363]  red_dequeue+0x65/0x270 [sch_red] [   78.673217][  T363]  ? srso_alias_return_thunk+0x5/0xfbef5 [   78.673385][  T363]  tbf_dequeue.cold+0xb0/0x70c [sch_tbf] [   78.673566][  T363]  __qdisc_run+0x169/0x1900  The right thing to do in #1b is to grab the skb off gso_skb queue. This patchset fixes that issue by changing #1b to use qdisc_dequeue_peeked() method instead.",
  "id": "DEBIAN-CVE-2026-43496",
  "modified": "2026-09-14T16:47:35.464403257Z",
  "published": "2026-05-21T13:16:18.960Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-43496"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-43496"
  ]
}