CVE-2026-43496

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-05-21. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: None knownExposed: 0

A fix is available — apply it.

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 <80> 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] [ 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.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity55% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

May 21, 2026

Last Modified

July 23, 2026

Advisory Details (8)

Auto-updated Jun 26, 2026
No patch confirmed yet.
generic

net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ce051eede433f876d322ac3550a36a3c6fc4c231
generic

net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c7335f4dc0fa21f7015b910c6fc2f4d599732328
generic

net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8d09618840b99ef00154d3e731ce9b11e096196d
generic

net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/587dcf970a525f543d8b5855d9f37a4ca97b76ef
generic

net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/45cd83c5c470ba49fe261489c8358ad7b9df7c45
generic

net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/458d5615272d3de535748342eb68ca492343048c
generic

net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/36aa34f42cb6842cf371f3a2d3e855d24fd57a50
generic

net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/03b0aaeba082ae981a0dfe96cdd03d02050537a1

Vendor Advisories for CVE-2026-43496(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(31)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-28.28) @ resolute2026-08-23ubuntu
ubuntulinux-xilinx-zynqmp-tools-5.15.0-1075 (5.15.0-1075.79) @ jammy2026-08-23ubuntu
ubuntulinux-tools-nvidia-tegra-rt-5.15 (5.15.0.1064.66~20.04.1) @ focal2026-08-23ubuntu
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-08-23ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1064.72+fips1) @ noble2026-08-23ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1059.62.1) @ noble2026-08-23ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-136.136~22.04.1) @ jammy2026-08-23ubuntu
ubuntulinux-tools-oracle-edge (5.15.0.1109.115~20.04.1) @ focal2026-08-23ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1058.61~22.04.1) @ jammy2026-08-23ubuntu
ubuntulinux-tools-intel-iotg-5.15 (5.15.0.1107.106) @ jammy2026-08-23ubuntu
ubuntulinux-virtual-hwe-24.04-edge (7.0.0-28.28~24.04.1) @ noble2026-08-23ubuntu
ubuntulinux-tools-nvidia-tegra-rt-5.15 (5.15.0.1064.64) @ jammy2026-08-23ubuntu
ubuntulinux-tools-ibm-edge (5.15.0.1106.110~20.04.1) @ focal2026-08-23ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-08-23ubuntu
ubuntulinux-tools-aws-lts-24.04 (6.8.0-1061.64+1) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-fde-lts-24.04 (6.8.0-1062.69) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1063.71+fips2) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-fde-6.8 (6.8.0-1062.69~22.04.1) @ jammy2026-08-23ubuntu
ubuntulinux-tools-azure-fde-lts-22.04 (5.15.0.1117.126) @ jammy2026-08-23ubuntu
ubuntulinux-virtual-6.8 (6.8.0-136.136) @ noble2026-08-23ubuntu
ubuntulinux-tools-oem-7.0 (7.0.0-1009.9) @ resolute2026-08-23ubuntu
ubuntulinux-tools-aws-fips-6.8 (6.8.0-1061.64+fips1) @ noble2026-08-23ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-08-23ubuntu
ubuntulinux-tools-nvidia-lowlatency-5.15 (5.15.0.1107.107) @ jammy2026-08-23ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2050.52) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1063.71) @ noble2026-08-23ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1058.61) @ noble2026-08-23ubuntu
ubuntulinux-tools-gcp-edge (5.15.0.1112.122~20.04.1) @ focal2026-08-23ubuntu
ubuntulinux-tools-azure-fips-5.15 (5.15.0.1117.102) @ jammy2026-08-23ubuntu
ubuntulinux-tools-intel-iotg-edge (5.15.0.1107.113~20.04.1) @ focal2026-08-23ubuntu
linuxKernel @ 5.10.258—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (54 versions)5.10.259-1—
linux-6.16.1.106-3~deb11u1 ... 6.1.174-1~deb11u1 (20 versions)6.1.176-1~deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (53 versions)6.1.176-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.88-1~bpo12+1 (21 versions)6.12.88-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.7-1~bpo13+1 (133 versions)7.0.7-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(24)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 4× in last 7d / 58× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 183 total refreshes for this CVE.

  1. 2026-09-04 05:06 UTCEPSS rescore
  2. 2026-09-02 14:12 UTCEPSS rescore
  3. 2026-09-01 13:54 UTCEPSS rescore
  4. 2026-08-30 19:17 UTCEPSS rescore
  5. 2026-08-28 21:41 UTCEPSS rescore
  6. 2026-08-27 14:25 UTCEPSS rescore
  7. 2026-08-26 14:46 UTCEPSS rescore
  8. 2026-08-23 16:50 UTCVendor advisory
  9. 2026-08-23 16:50 UTCGHSA enrichment
  10. 2026-08-21 21:47 UTCEG score recompute
  11. 2026-08-21 21:47 UTCVendor advisory
  12. 2026-08-21 21:47 UTCGHSA enrichment
  13. 2026-08-20 22:55 UTCEPSS rescore
  14. 2026-08-20 18:50 UTCEG score recompute
  15. 2026-08-20 18:50 UTCVendor advisory
  16. 2026-08-20 18:49 UTCGHSA enrichment
  17. 2026-08-19 17:04 UTCEPSS rescore
  18. 2026-08-18 13:48 UTCEPSS rescore
  19. 2026-08-17 09:49 UTCEG score recompute
  20. 2026-08-17 09:49 UTCVendor advisory
  21. 2026-08-17 09:49 UTCGHSA enrichment
  22. 2026-08-16 14:56 UTCEPSS rescore
  23. 2026-08-16 03:25 UTCEG score recompute
  24. 2026-08-16 03:25 UTCVendor advisory
  25. 2026-08-16 03:25 UTCGHSA enrichment
Show 75 more
  1. 2026-08-16 02:14 UTCEPSS rescore
  2. 2026-08-15 01:30 UTCEPSS rescore
  3. 2026-08-14 11:20 UTCEG score recompute
  4. 2026-08-14 11:20 UTCVendor advisory
  5. 2026-08-14 11:20 UTCGHSA enrichment
  6. 2026-08-13 22:00 UTCEPSS rescore
  7. 2026-08-13 10:45 UTCEG score recompute
  8. 2026-08-13 10:45 UTCVendor advisory
  9. 2026-08-13 10:45 UTCGHSA enrichment
  10. 2026-08-12 13:51 UTCEPSS rescore
  11. 2026-08-12 09:51 UTCEG score recompute
  12. 2026-08-12 09:51 UTCVendor advisory
  13. 2026-08-12 09:50 UTCGHSA enrichment
  14. 2026-08-11 13:43 UTCEPSS rescore
  15. 2026-08-11 02:31 UTCEG score recompute
  16. 2026-08-11 02:31 UTCVendor advisory
  17. 2026-08-11 02:30 UTCGHSA enrichment
  18. 2026-08-11 00:00 UTCEPSS rescore
  19. 2026-08-10 01:59 UTCEG score recompute
  20. 2026-08-10 01:59 UTCVendor advisory
  21. 2026-08-10 01:59 UTCGHSA enrichment
  22. 2026-08-09 13:46 UTCEPSS rescore
  23. 2026-08-09 01:28 UTCEG score recompute
  24. 2026-08-09 01:28 UTCVendor advisory
  25. 2026-08-09 01:28 UTCGHSA enrichment
  26. 2026-08-08 16:37 UTCEPSS rescore
  27. 2026-08-07 22:16 UTCEG score recompute
  28. 2026-08-07 22:16 UTCVendor advisory
  29. 2026-08-07 22:16 UTCGHSA enrichment
  30. 2026-08-06 21:45 UTCEG score recompute
  31. 2026-08-06 21:45 UTCVendor advisory
  32. 2026-08-06 21:45 UTCGHSA enrichment
  33. 2026-08-06 13:46 UTCEPSS rescore
  34. 2026-08-05 21:14 UTCEG score recompute
  35. 2026-08-05 21:14 UTCVendor advisory
  36. 2026-08-05 21:14 UTCGHSA enrichment
  37. 2026-08-05 19:17 UTCEPSS rescore
  38. 2026-08-04 15:10 UTCEPSS rescore
  39. 2026-08-04 10:38 UTCEPSS rescore
  40. 2026-08-03 18:46 UTCEG score recompute
  41. 2026-08-03 18:46 UTCVendor advisory
  42. 2026-08-03 18:46 UTCGHSA enrichment
  43. 2026-08-03 10:36 UTCEPSS rescore
  44. 2026-08-02 18:04 UTCVendor advisory
  45. 2026-08-02 18:04 UTCGHSA enrichment
  46. 2026-08-01 17:32 UTCEG score recompute
  47. 2026-08-01 17:32 UTCVendor advisory
  48. 2026-08-01 17:32 UTCGHSA enrichment
  49. 2026-08-01 04:16 UTCEPSS rescore
  50. 2026-07-30 16:28 UTCEPSS rescore
  51. 2026-07-30 01:30 UTCEPSS rescore
  52. 2026-07-29 17:59 UTCEG score recompute
  53. 2026-07-29 17:59 UTCVendor advisory
  54. 2026-07-29 17:59 UTCGHSA enrichment
  55. 2026-07-28 15:36 UTCEPSS rescore
  56. 2026-07-27 14:13 UTCEPSS rescore
  57. 2026-07-26 14:54 UTCEPSS rescore
  58. 2026-07-26 14:54 UTCEPSS rescore
  59. 2026-07-26 08:11 UTCEG score recompute
  60. 2026-07-26 08:11 UTCVendor advisory
  61. 2026-07-26 08:11 UTCGHSA enrichment
  62. 2026-07-25 14:18 UTCEPSS rescore
  63. 2026-07-24 14:17 UTCEPSS rescore
  64. 2026-07-23 14:18 UTCEPSS rescore
  65. 2026-07-23 03:14 UTCEG score recompute
  66. 2026-07-22 14:08 UTCEPSS rescore
  67. 2026-07-21 15:24 UTCEPSS rescore
  68. 2026-07-20 17:08 UTCEPSS rescore
  69. 2026-07-19 14:31 UTCEPSS rescore
  70. 2026-07-19 02:29 UTCEPSS rescore
  71. 2026-07-18 10:04 UTCEPSS rescore
  72. 2026-07-17 22:29 UTCOSV refresh
  73. 2026-07-16 17:03 UTCEPSS rescore
  74. 2026-07-15 16:57 UTCEPSS rescore
  75. 2026-07-15 02:00 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-43496?
CVE-2026-43496 is a medium vulnerability published on May 21, 2026. In the Linux kernel, the following vulnerability has been resolved: net/sched: schred: Replace direct dequeue call with peek and qdiscdequeue_peeked When red qdisc has children (eg qfq qdisc) whose peek() callback is qdiscpeekdequeued(), we could get a kernel panic. When the parent of such qdiscs…
When was CVE-2026-43496 disclosed?
CVE-2026-43496 was first published in the National Vulnerability Database on May 21, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43496 actively exploited?
CVE-2026-43496 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 98.1% of all scored CVEs.
What is the CVSS score of CVE-2026-43496?
CVE-2026-43496 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-43496?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43496, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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