CVE-2026-43027

HIGHNVD 7.87.8
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-01. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack_helper: pass helper to expect cleanup

nf_conntrack_helper_unregister() calls nf_ct_expect_iterate_destroy() to remove expectations belonging to the helper being unregistered. However, it passes NULL instead of the helper pointer as the data argument, so expect_iter_me() never matches any expectation and all of them survive the cleanup.

After unregister returns, nfnl_cthelper_del() frees the helper object immediately. Subsequent expectation dumps or packet-driven init_conntrack() calls then dereference the freed exp->helper, causing a use-after-free.

Pass the actual helper pointer so expectations referencing it are properly destroyed before the helper object is freed.

BUG: KASAN: slab-use-after-free in string+0x38f/0x430 Read of size 1 at addr ffff888003b14d20 by task poc/103 Call Trace: string+0x38f/0x430 vsnprintf+0x3cc/0x1170 seq_printf+0x17a/0x240 exp_seq_show+0x2e5/0x560 seq_read_iter+0x419/0x1280 proc_reg_read+0x1ac/0x270 vfs_read+0x179/0x930 ksys_read+0xef/0x1c0 Freed by task 103: The buggy address is located 32 bytes inside of freed 192-byte region [ffff888003b14d00, ffff888003b14dc0)

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity78% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
3%
KEV
Not listed

Published

May 1, 2026

Last Modified

July 14, 2026

Advisory Details (8)

Auto-updated May 8, 2026
No patch confirmed yet.
generic

netfilter: nf_conntrack_helper: pass helper to expect cleanup - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/dc1739eff48e34cc71d4e2f03715493fbcebd8af
generic

netfilter: nf_conntrack_helper: pass helper to expect cleanup - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a242a9ae58aa46ff7dae51ce64150a93957abe65
generic

netfilter: nf_conntrack_helper: pass helper to expect cleanup - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/90bd7e8501349db3006d21fbc09df9ffcb172965
generic

netfilter: nf_conntrack_helper: pass helper to expect cleanup - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/620f3d14c1ef51d425060a3056ad8dbae8f998a3
generic

netfilter: nf_conntrack_helper: pass helper to expect cleanup - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5cf28d5c8dcbbe8af6d3b145babe491906d7bad1
generic

netfilter: nf_conntrack_helper: pass helper to expect cleanup - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/504ba4168466c91210c45acdc332479cfd5f2da6
generic

netfilter: nf_conntrack_helper: pass helper to expect cleanup - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2cf2737c85a2ba2b52024dafe68ffad2676f97be
generic

netfilter: nf_conntrack_helper: pass helper to expect cleanup - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2c16e4d64dd91227742dfe196a3e7b0568bef65a

Patch Availability(31)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1063.71+fips2) @ noble2026-08-23ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1058.61) @ noble2026-08-23ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1058.61~22.04.1) @ jammy2026-08-23ubuntu
ubuntulinux-tools-azure-fde-6.8 (6.8.0-1062.69~22.04.1) @ jammy2026-08-23ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1059.62.1) @ noble2026-08-23ubuntu
ubuntulinux-tools-nvidia-lowlatency-5.15 (5.15.0.1107.107) @ jammy2026-08-23ubuntu
ubuntulinux-tools-intel-iotg-edge (5.15.0.1107.113~20.04.1) @ focal2026-08-23ubuntu
ubuntulinux-tools-azure-fde-lts-22.04 (5.15.0.1117.126) @ jammy2026-08-23ubuntu
ubuntulinux-tools-oracle-lts-22.04 (5.15.0.1109.105) @ jammy2026-08-23ubuntu
ubuntulinux-tools-aws-fips-6.8 (6.8.0-1061.64+fips1) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-fips-5.15 (5.15.0.1117.102) @ jammy2026-08-23ubuntu
ubuntulinux-tools-nvidia-tegra-rt-5.15 (5.15.0.1064.64) @ jammy2026-08-23ubuntu
ubuntulinux-tools-gcp-edge (5.15.0.1112.122~20.04.1) @ focal2026-08-23ubuntu
ubuntulinux-tools-intel-iotg-5.15 (5.15.0.1107.106) @ jammy2026-08-23ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2050.52) @ noble2026-08-23ubuntu
ubuntulinux-tools-realtime-hwe-22.04 (6.8.1-1056.57~22.04.2) @ jammy2026-08-23ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1064.72+fips1) @ noble2026-08-23ubuntu
ubuntulinux-xilinx-zynqmp-tools-5.15.0-1075 (5.15.0-1075.79) @ jammy2026-08-23ubuntu
redhatkernel-0:4.18.0-305.199.1.el8_42026-07-30redhat
redhatkernel-0:4.18.0-477.152.1.el8_82026-07-16redhat
redhatkernel-0:4.18.0-372.201.1.el8_62026-07-15redhat
redhatkernel-0:5.14.0-284.181.1.el9_22026-07-15redhat
redhatkernel-rt-0:5.14.0-284.181.1.rt14.466.el9_22026-07-15redhat
redhatkernel-0:6.12.0-55.88.1.el10_02026-07-14redhat
redhatkernel-0:5.14.0-427.136.1.el9_42026-07-08redhat
redhatkernel-0:5.14.0-570.125.1.el9_62026-07-01redhat
redhatkernel-0:5.14.0-687.12.1.el9_82026-05-28redhat
redhatkernel-0:6.12.0-211.18.1.el10_22026-05-28redhat
redhatkernel-rt-0:4.18.0-553.126.1.rt7.467.el8_102026-05-28redhat
redhatkernel-0:4.18.0-553.126.1.el8_102026-05-28redhat
linuxKernel @ 5.10.253osv

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 (53 versions)5.10.257-1
linux-6.16.1.106-3~deb11u1 ... 6.1.164-1~deb11u1 (16 versions)6.1.170-1~deb11u1
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (48 versions)6.1.170-1
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.85-1~bpo12+1 (17 versions)6.12.85-1
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 6.19~rc8-1~exp1 (122 versions)6.19.12-1

Weakness Classification(1)

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

Additional Vendor Advisories

(13)

Data Freshness Timeline

(refreshed 8× in last 7d / 88× 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 227 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-43027?
CVE-2026-43027 is a high vulnerability published on May 1, 2026. In the Linux kernel, the following vulnerability has been resolved: netfilter: nfconntrackhelper: pass helper to expect cleanup nfconntrackhelperunregister() calls nfctexpectiterate_destroy() to remove expectations belonging to the helper being unregistered. However, it passes NULL instead of the…
When was CVE-2026-43027 disclosed?
CVE-2026-43027 was first published in the National Vulnerability Database on May 1, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43027 actively exploited?
CVE-2026-43027 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 97.0% of all scored CVEs.
What is the CVSS score of CVE-2026-43027?
CVE-2026-43027 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-43027?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43027, 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.

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