CVE-2026-23231: netfilter: nf_tables: fix use-after-free in nf_tables_addchain()

Published Mar 4, 2026
·
Updated

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

netfilter: nftables: fix use-after-free in nftablesaddchain()

nftablesaddchain() publishes the chain to table->chains via listaddtailrcu() (in nftchainadd()) before registering hooks. If nftablesregisterhook() then fails, the error path calls nftchaindel() (listdelrcu()) followed by nftableschaindestroy() with no RCU grace period in between.

This creates two use-after-free conditions:

1) Control-plane: nftablesdumpchains() traverses table->chains under rcureadlock(). A concurrent dump can still be walking the chain when the error path frees it.

2) Packet path: for NFPROTOINET, nfregisternethook() briefly installs the IPv4 hook before IPv6 registration fails. Packets entering nftdochain() via the transient IPv4 hook can still be dereferencing chain->blobgenX when the error path frees the chain.

Add synchronizercu() between nftchaindel() and the chain destroy so that all RCU readers -- both dump threads and in-flight packet evaluation -- have finished before the chain is freed.

Affected Software

166 affected componentsFixes available
linux_kernel
Microsoft azl3 kernel 6.6.126.1-1<6.6.130.1-1
6.6.130.1-1
Linux Linux kernel>=3.16<6.1.165
Linux Linux kernel>=6.2<6.6.128
Linux Linux kernel>=6.7<6.12.75
Linux Linux kernel>=6.13<6.18.14
Linux Linux kernel>=6.19<6.19.4
debian/linux<6.1.170-1
6.1.170-1
debian/linux<6.12.85-1
6.12.85-1
debian/linux<6.18.14-1
6.18.14-1
ubuntu/linux-hwe-edge*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-azure*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.8*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.8*
ubuntu/linux-gke*
ubuntu/linux-gke-5.15*
ubuntu/linux-gkeop*
ubuntu/linux-gkeop-5.15*
ubuntu/linux-hwe-5.11*
ubuntu/linux-hwe-5.13*
ubuntu/linux-hwe-5.8*
ubuntu/linux-intel-5.13*
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.8*
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-aws-6.8<6.8.0-1053.56~22.04.1
6.8.0-1053.56~22.04.1
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8<6.8.0-1059.65~22.04.1
6.8.0-1059.65~22.04.1
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-azure-fde-6.8<6.8.0-1058.65~22.04.1
6.8.0-1058.65~22.04.1
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8<6.8.0-1060.63~22.04.1
6.8.0-1060.63~22.04.1
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-hwe-6.8<6.8.0-111.111~22.04.1
6.8.0-111.111~22.04.1
ubuntu/linux-ibm-6.8<6.8.0-1052.52~22.04.1
6.8.0-1052.52~22.04.1
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-lowlatency-hwe-6.8<6.8.0-111.111.1~22.04.1
6.8.0-111.111.1~22.04.1
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8<6.8.0-1052.55~22.04.1
6.8.0-1052.55~22.04.1
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle-6.5*
ubuntu/linux-oracle-6.8<6.8.0-1050.51~22.04.1
6.8.0-1050.51~22.04.1
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8<6.8.0-111.111~22.04.1
6.8.0-111.111~22.04.1
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-realtime-6.8<6.8.1-1048.49~22.04.1
6.8.1-1048.49~22.04.1
ubuntu/linux<6.8.0-111.111
6.8.0-111.111
ubuntu/linux-aws<6.8.0-1053.56
6.8.0-1053.56
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17<6.17.0-1013.13~24.04.1
6.17.0-1013.13~24.04.1
ubuntu/linux-azure<6.8.0-1054.60
6.8.0-1054.60
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-6.17<6.17.0-1013.13~24.04.1
6.17.0-1013.13~24.04.1
ubuntu/linux-azure-fde<6.8.0-1058.65
6.8.0-1058.65
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-nvidia<6.8.0-1039.42
6.8.0-1039.42
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp<6.8.0-1055.58
6.8.0-1055.58
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gcp-6.17<6.17.0-1013.13~24.04.1
6.17.0-1013.13~24.04.1
ubuntu/linux-gke<6.8.0-1051.57
6.8.0-1051.57
ubuntu/linux-gkeop<6.8.0-1038.41
6.8.0-1038.41
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-hwe-6.17<6.17.0-23.23~24.04.1
6.17.0-23.23~24.04.1
ubuntu/linux-ibm<6.8.0-1052.52
6.8.0-1052.52
ubuntu/linux-lowlatency<6.8.0-111.111.1
6.8.0-111.111.1
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia<6.8.0-1052.55
6.8.0-1052.55
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-6.17<6.17.0-1026.26
6.17.0-1026.26
ubuntu/linux-nvidia-lowlatency<6.8.0-1052.55.1
6.8.0-1052.55.1
ubuntu/linux-nvidia-tegra<6.8.0-1023.23
6.8.0-1023.23
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14*
ubuntu/linux-oem-6.17<6.17.0-1020.20
6.17.0-1020.20
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle<6.8.0-1050.51
6.8.0-1050.51
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17<6.17.0-1014.14~24.04.1
6.17.0-1014.14~24.04.1
ubuntu/linux-raspi<6.8.0-1053.57
6.8.0-1053.57
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14*
ubuntu/linux-riscv-6.17<6.17.0-23.23.1~24.04.1
6.17.0-23.23.1~24.04.1
ubuntu/linux-xilinx<6.8.0-1029.30
6.8.0-1029.30
ubuntu/linux-bluefield<6.8.0-1022.26
6.8.0-1022.26
ubuntu/linux-raspi-realtime<6.8.0-2043.44
6.8.0-2043.44
ubuntu/linux-realtime<6.8.1-1048.49
6.8.1-1048.49
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17<6.17.0-1011.12~24.04.1
6.17.0-1011.12~24.04.1
ubuntu/linux-aws-fips<6.8.0-1053.56+fips1
6.8.0-1053.56+fips1
ubuntu/linux-azure-fips<6.8.0-1054.60+fips1
6.8.0-1054.60+fips1
ubuntu/linux-fips<6.8.0-111.111+fips1
6.8.0-111.111+fips1
ubuntu/linux-gcp-fips<6.8.0-1055.58+fips1
6.8.0-1055.58+fips1
ubuntu/linux<6.17.0-23.23
6.17.0-23.23
ubuntu/linux-aws<6.17.0-1013.13
6.17.0-1013.13
ubuntu/linux-azure<6.17.0-1013.13
6.17.0-1013.13
ubuntu/linux-azure-fde*
ubuntu/linux-gcp<6.17.0-1013.13
6.17.0-1013.13
ubuntu/linux-oracle<6.17.0-1012.12
6.17.0-1012.12
ubuntu/linux-raspi<6.17.0-1014.14
6.17.0-1014.14
ubuntu/linux-realtime<6.17.0-1011.12
6.17.0-1011.12
ubuntu/linux-riscv<6.17.0-23.23.1
6.17.0-23.23.1
ubuntu/linux-vmware*
linux/kernel>=3.16.0<6.1.165
6.1.165
linux/kernel>=6.2.0<6.6.128
6.6.128
linux/kernel>=6.7.0<6.12.75
6.12.75
linux/kernel>=6.13.0<6.18.14
6.18.14
linux/kernel>=6.19.0<6.19.4
6.19.4
debian/linux
6.1.176-16.1.190-16.12.107-16.12.116-17.2.15-17.3.4-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.6.130.1-1
  2. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 6.1.170-1
  3. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 6.12.85-1
  4. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 6.18.14-1
  5. Upgrade

    Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1053.56~22.04.1
  6. Upgrade

    Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1059.65~22.04.1
  7. Upgrade

    Upgrade ubuntu/linux-azure-fde-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1058.65~22.04.1
  8. Upgrade

    Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1060.63~22.04.1
  9. Upgrade

    Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-111.111~22.04.1
  10. Upgrade

    Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1052.52~22.04.1
  11. Upgrade

    Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-111.111.1~22.04.1
  12. Upgrade

    Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1052.55~22.04.1
  13. Upgrade

    Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1050.51~22.04.1
  14. Upgrade

    Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-111.111~22.04.1
  15. Upgrade

    Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.1-1048.49~22.04.1
  16. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 6.8.0-111.111
  17. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 6.8.0-1053.56
  18. Upgrade

    Upgrade ubuntu/linux-aws-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1013.13~24.04.1
  19. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 6.8.0-1054.60
  20. Upgrade

    Upgrade ubuntu/linux-azure-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1013.13~24.04.1
  21. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 6.8.0-1058.65
  22. Upgrade

    Upgrade ubuntu/linux-azure-nvidia to a version that resolves this vulnerability.

    Fixed in 6.8.0-1039.42
  23. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 6.8.0-1055.58
  24. Upgrade

    Upgrade ubuntu/linux-gcp-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1013.13~24.04.1
  25. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 6.8.0-1051.57
  26. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 6.8.0-1038.41
  27. Upgrade

    Upgrade ubuntu/linux-hwe-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-23.23~24.04.1
  28. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 6.8.0-1052.52
  29. Upgrade

    Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.

    Fixed in 6.8.0-111.111.1
  30. Upgrade

    Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.

    Fixed in 6.8.0-1052.55
  31. Upgrade

    Upgrade ubuntu/linux-nvidia-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1026.26
  32. Upgrade

    Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.

    Fixed in 6.8.0-1052.55.1
  33. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.

    Fixed in 6.8.0-1023.23
  34. Upgrade

    Upgrade ubuntu/linux-oem-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1020.20
  35. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 6.8.0-1050.51
  36. Upgrade

    Upgrade ubuntu/linux-oracle-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1014.14~24.04.1
  37. Upgrade

    Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.

    Fixed in 6.8.0-1053.57
  38. Upgrade

    Upgrade ubuntu/linux-riscv-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-23.23.1~24.04.1
  39. Upgrade

    Upgrade ubuntu/linux-xilinx to a version that resolves this vulnerability.

    Fixed in 6.8.0-1029.30
  40. Upgrade

    Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.

    Fixed in 6.8.0-1022.26
  41. Upgrade

    Upgrade ubuntu/linux-raspi-realtime to a version that resolves this vulnerability.

    Fixed in 6.8.0-2043.44
  42. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 6.8.1-1048.49
  43. Upgrade

    Upgrade ubuntu/linux-realtime-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1011.12~24.04.1
  44. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1053.56+fips1
  45. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1054.60+fips1
  46. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-111.111+fips1
  47. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1055.58+fips1
  48. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 6.17.0-23.23
  49. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 6.17.0-1013.13
  50. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 6.17.0-1013.13
  51. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 6.17.0-1013.13
  52. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 6.17.0-1012.12
  53. Upgrade

    Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.

    Fixed in 6.17.0-1014.14
  54. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 6.17.0-1011.12
  55. Upgrade

    Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.

    Fixed in 6.17.0-23.23.1
  56. Upgrade

    Upgrade linux/Kernel to a version that resolves this vulnerability.

    Fixed in 6.1.165
  57. Upgrade

    Upgrade linux/Kernel to a version that resolves this vulnerability.

    Fixed in 6.6.128
  58. Upgrade

    Upgrade linux/Kernel to a version that resolves this vulnerability.

    Fixed in 6.12.75
  59. Upgrade

    Upgrade linux/Kernel to a version that resolves this vulnerability.

    Fixed in 6.18.14
  60. Upgrade

    Upgrade linux/Kernel to a version that resolves this vulnerability.

    Fixed in 6.19.4
  61. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.116-1Fixed in 7.2.15-1Fixed in 7.3.4-1
  62. Compensating control

    In kernel code, add synchronize_rcu() between nft_chain_del() (list_del_rcu()) and the chain destroy (nf_tables_chain_destroy()) so all RCU readers (dump threads and in-flight packet evaluation) finish before the chain is freed.

Event History

Mar 4, 2026
CVE Published
via MITRE·12:58 PM
Data Sourced
via MITRE·12:58 PM
DescriptionSeverity
Data Sourced
via OSV·12:58 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·01:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Data Sourced
via Red Hat·02:01 PM
DescriptionSeverityAffected Software
Mar 5, 2026
Data Sourced
via Microsoft·09:04 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·09:04 AM
Affected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What is the severity of CVE-2026-23231?

CVE-2026-23231 is classified as a high severity vulnerability due to the potential for use-after-free exploits in the Linux kernel.

2

How do I fix CVE-2026-23231?

To fix CVE-2026-23231, update the Linux kernel to the latest patched version provided by your distribution.

3

What systems are affected by CVE-2026-23231?

CVE-2026-23231 affects systems running vulnerable versions of the Linux kernel with netfilter's nf_tables feature.

4

What are the risks associated with CVE-2026-23231?

The risks associated with CVE-2026-23231 include potential remote code execution or system crashes due to the use-after-free vulnerability.

5

How can I determine if my system is vulnerable to CVE-2026-23231?

You can determine if your system is vulnerable to CVE-2026-23231 by checking the kernel version and ensuring it has been updated to the latest secure release.

Company

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Contact

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