CVE-2026-43329

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-08. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.8Exploit: NoneExposed: 0

A fix is available — apply it.

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

netfilter: flowtable: strictly check for maximum number of actions

The maximum number of flowtable hardware offload actions in IPv6 is:

* ethernet mangling (4 payload actions, 2 for each ethernet address) * SNAT (4 payload actions) * DNAT (4 payload actions) * Double VLAN (4 vlan actions, 2 for popping vlan, and 2 for pushing) for QinQ. * Redirect (1 action)

Which makes 17, while the maximum is 16. But act_ct supports for tunnels actions too. Note that payload action operates at 32-bit word level, so mangling an IPv6 address takes 4 payload actions.

Update flow_action_entry_next() calls to check for the maximum number of supported actions.

While at it, rise the maximum number of actions per flow from 16 to 24 so this works fine with IPv6 setups.

CVSS v3
7.8
EG Score
7.8(medium)
EPSS
3.9%
KEV
Not listed

Published

May 8, 2026

Last Modified

July 22, 2026

Advisory Details (7)

Auto-updated May 11, 2026
No patch confirmed yet.
generic

netfilter: flowtable: strictly check for maximum number of actions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/fe9018d3e94329f1951b00805a8640bc06f56ead
generic

netfilter: flowtable: strictly check for maximum number of actions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ead66c77303f760f6c30be96e2e20d5a77cef614
generic

netfilter: flowtable: strictly check for maximum number of actions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/879959a7a2be814dd57568655eafa3d8f4d0309e
generic

netfilter: flowtable: strictly check for maximum number of actions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/76522fcdbc3a02b568f5d957f7e66fc194abb893
generic

netfilter: flowtable: strictly check for maximum number of actions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/57c78bd2e2dd08897acd35b2bf8bcef322e36f5e
generic

netfilter: flowtable: strictly check for maximum number of actions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5382bb03e9c33b089d60788478b922a2dca284cc
generic

netfilter: flowtable: strictly check for maximum number of actions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/504c9456699dcf4d15195ef34a0fa94a80bfc877

Vendor Advisories for CVE-2026-43329(13)

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

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatkernel-0:5.14.0-427.134.1.el9_42026-06-22redhat
redhatkernel-rt-0:4.18.0-553.134.1.rt7.475.el8_102026-06-16redhat
redhatkernel-0:4.18.0-553.134.1.el8_102026-06-16redhat
redhatkernel-0:6.12.0-211.20.1.el10_22026-06-04redhat
linuxKernel @ 5.15.203—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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 34× 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 129 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-43329?
CVE-2026-43329 is a high vulnerability published on May 8, 2026. In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: strictly check for maximum number of actions The maximum number of flowtable hardware offload actions in IPv6 is: ethernet mangling (4 payload actions, 2 for each ethernet address) SNAT (4 payload actions)…
When was CVE-2026-43329 disclosed?
CVE-2026-43329 was first published in the National Vulnerability Database on May 8, 2026, with the most recent update on July 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43329 actively exploited?
CVE-2026-43329 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-43329?
CVE-2026-43329 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-43329?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43329, 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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