CVE-2026-31709: smb: client: validate the whole DACL before rewriting it in cifsacl

Published May 1, 2026
·
Updated

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

smb: client: validate the whole DACL before rewriting it in cifsacl

buildsecdesc() and idmodetocifsacl() derive a DACL pointer from a server-supplied dacloffset and then use the incoming ACL to rebuild the chmod/chown security descriptor.

The original fix only checked that the struct smbacl header fits before reading daclptr->size or daclptr->numaces. That avoids the immediate header-field OOB read, but the rewrite helpers still walk ACEs based on pdacl->numaces with no structural validation of the incoming DACL body.

A malicious server can return a truncated DACL that still contains a header, claims one or more ACEs, and then drive replacesidsandcopyaces() or setchmoddacl() past the validated extent while they compare or copy attacker-controlled ACEs.

Factor the DACL structural checks into validatedacl(), extend them to validate each ACE against the DACL bounds, and use the shared validator before the chmod/chown rebuild paths. parsedacl() reuses the same validator so the read-side parser and write-side rewrite paths agree on what constitutes a well-formed incoming DACL.

Affected Software

210 affected componentsFixes available
The Linux Foundation Linux Kernel
Linux Linux kernel>=5.12<7.0.2
linux/kernel>=5.12.0<5.15.210
5.15.210
linux/kernel>=5.16.0<6.1.176
6.1.176
linux/kernel>=6.2.0<6.6.140
6.6.140
linux/kernel>=6.7.0<6.12.86
6.12.86
linux/kernel>=6.13.0<6.18.35
6.18.35
linux/kernel>=6.19.0<7.0.2
7.0.2
debian/linux
6.1.176-16.1.190-16.12.107-16.12.116-17.2.15-17.3.3-1
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-5.15<5.15.0-1117.124~20.04.1
5.15.0-1117.124~20.04.1
ubuntu/linux-aws-5.8*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.15<5.15.0-1123.132~20.04.1
5.15.0-1123.132~20.04.1
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-5.15<5.15.0-1122.131~20.04.1
5.15.0-1122.131~20.04.1
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.15<5.15.0-1118.128~20.04.1
5.15.0-1118.128~20.04.1
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-5.15<5.15.0-198.208~20.04.1
5.15.0-198.208~20.04.1
ubuntu/linux-hwe-5.8*
ubuntu/linux-ibm-5.15<5.15.0-1111.115~20.04.1
5.15.0-1111.115~20.04.1
ubuntu/linux-intel-5.13*
ubuntu/linux-intel-iotg-5.15<5.15.0-1112.118~20.04.1
5.15.0-1112.118~20.04.1
ubuntu/linux-lowlatency-hwe-5.15<5.15.0-195.205~20.04.1
5.15.0-195.205~20.04.1
ubuntu/linux-nvidia-tegra-5.15<5.15.0-1070.72~20.04.1
5.15.0-1070.72~20.04.1
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-5.15<5.15.0-1114.120~20.04.1
5.15.0-1114.120~20.04.1
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.15<5.15.0-1111.115~20.04.1
5.15.0-1111.115~20.04.1
ubuntu/linux-riscv-5.8*
ubuntu/linux<5.15.0-198.208
5.15.0-198.208
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws<5.15.0-1117.124
5.15.0-1117.124
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-aws-6.8<6.8.0-1061.64~22.04.1
6.8.0-1061.64~22.04.1
ubuntu/linux-azure<5.15.0-1123.132
5.15.0-1123.132
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8<6.8.0-1063.71~22.04.1
6.8.0-1063.71~22.04.1
ubuntu/linux-azure-fde<5.15.0-1122.131
5.15.0-1122.131
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-azure-fde-6.8<6.8.0-1062.69~22.04.1
6.8.0-1062.69~22.04.1
ubuntu/linux-gcp<5.15.0-1118.128
5.15.0-1118.128
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8<6.8.0-1064.72~22.04.1
6.8.0-1064.72~22.04.1
ubuntu/linux-gke<5.15.0-1113.119
5.15.0-1113.119
ubuntu/linux-gkeop<5.15.0-1100.108
5.15.0-1100.108
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-hwe-6.8<6.8.0-136.136~22.04.1
6.8.0-136.136~22.04.1
ubuntu/linux-ibm<5.15.0-1111.115
5.15.0-1111.115
ubuntu/linux-ibm-6.8<6.8.0-1061.62~22.04.1
6.8.0-1061.62~22.04.1
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-intel-iotg<5.15.0-1112.118
5.15.0-1112.118
ubuntu/linux-kvm<5.15.0-1109.114
5.15.0-1109.114
ubuntu/linux-lowlatency<5.15.0-195.205
5.15.0-195.205
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-lowlatency-hwe-6.8<6.8.0-136.136.2~22.04.1
6.8.0-136.136.2~22.04.1
ubuntu/linux-nvidia<5.15.0-1112.113
5.15.0-1112.113
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8<6.8.0-1059.62~22.04.1
6.8.0-1059.62~22.04.1
ubuntu/linux-nvidia-tegra<5.15.0-1070.72
5.15.0-1070.72
ubuntu/linux-nvidia-tegra-igx<5.15.0-1059.59
5.15.0-1059.59
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle<5.15.0-1114.120
5.15.0-1114.120
ubuntu/linux-oracle-6.5*
ubuntu/linux-oracle-6.8<6.8.0-1058.61~22.04.1
6.8.0-1058.61~22.04.1
ubuntu/linux-raspi<5.15.0-1113.116
5.15.0-1113.116
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8<6.8.0-136.136~22.04.3
6.8.0-136.136~22.04.3
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-xilinx-zynqmp<5.15.0-1080.84
5.15.0-1080.84
ubuntu/linux-bluefield<5.15.0-1101.103
5.15.0-1101.103
ubuntu/linux-intel-iot-realtime<5.15.0-1109.111
5.15.0-1109.111
ubuntu/linux-realtime<5.15.0-1116.125
5.15.0-1116.125
ubuntu/linux-realtime-6.8<6.8.1-1056.57~22.04.2
6.8.1-1056.57~22.04.2
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips<5.15.0-1117.124+fips1
5.15.0-1117.124+fips1
ubuntu/linux-azure-fips<5.15.0-1123.132+fips1
5.15.0-1123.132+fips1
ubuntu/linux-fips<5.15.0-198.208+fips1
5.15.0-198.208+fips1
ubuntu/linux-gcp-fips<5.15.0-1118.128+fips1
5.15.0-1118.128+fips1
ubuntu/linux<6.8.0-136.136
6.8.0-136.136
ubuntu/linux-aws<6.8.0-1061.64
6.8.0-1061.64
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17*
ubuntu/linux-azure<6.8.0-1063.71
6.8.0-1063.71
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-6.17*
ubuntu/linux-azure-fde<6.8.0-1062.69
6.8.0-1062.69
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-nvidia*
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp<6.8.0-1064.72
6.8.0-1064.72
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gke<6.8.0-1059.67
6.8.0-1059.67
ubuntu/linux-gkeop<6.8.0-1046.50
6.8.0-1046.50
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-hwe-6.17*
ubuntu/linux-hwe-7.0<7.0.0-28.28~24.04.1
7.0.0-28.28~24.04.1
ubuntu/linux-ibm<6.8.0-1061.62
6.8.0-1061.62
ubuntu/linux-lowlatency<6.8.0-136.136.2
6.8.0-136.136.2
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia<6.8.0-1059.62
6.8.0-1059.62
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-6.17*
ubuntu/linux-nvidia-lowlatency<6.8.0-1059.62.1
6.8.0-1059.62.1
ubuntu/linux-nvidia-tegra<6.8.0-1030.31
6.8.0-1030.31
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14*
ubuntu/linux-oem-6.17*
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle<6.8.0-1058.61
6.8.0-1058.61
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17*
ubuntu/linux-raspi<6.8.0-1061.65
6.8.0-1061.65
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14*
ubuntu/linux-riscv-6.17*
ubuntu/linux-vmware<6.8.0-1008.8
6.8.0-1008.8
ubuntu/linux-xilinx<6.8.0-1033.34
6.8.0-1033.34
ubuntu/linux-bluefield<6.8.0-1028.33
6.8.0-1028.33
ubuntu/linux-raspi-realtime<6.8.0-2050.52
6.8.0-2050.52
ubuntu/linux-realtime<6.8.1-1056.57
6.8.1-1056.57
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17*
ubuntu/linux-aws-fips<6.8.0-1061.64+fips1
6.8.0-1061.64+fips1
ubuntu/linux-azure-fips<6.8.0-1063.71+fips2
6.8.0-1063.71+fips2
ubuntu/linux-fips<6.8.0-136.136+fips2
6.8.0-136.136+fips2
ubuntu/linux-gcp-fips<6.8.0-1064.72+fips1
6.8.0-1064.72+fips1
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-azure*
ubuntu/linux-azure-fde*
ubuntu/linux-gcp*
ubuntu/linux-oracle*
ubuntu/linux-raspi*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux<7.0.0-27.27
7.0.0-27.27
ubuntu/linux-aws<7.0.0-1008.8
7.0.0-1008.8
ubuntu/linux-azure<7.0.0-1010.10
7.0.0-1010.10
ubuntu/linux-azure-fde<7.0.0-1009.9
7.0.0-1009.9
ubuntu/linux-gcp<7.0.0-1007.7
7.0.0-1007.7
ubuntu/linux-ibm<7.0.0-1009.9
7.0.0-1009.9
ubuntu/linux-nvidia<7.0.0-1013.13
7.0.0-1013.13
ubuntu/linux-oracle<7.0.0-1007.7
7.0.0-1007.7
ubuntu/linux-raspi<7.0.0-1014.14
7.0.0-1014.14
ubuntu/linux-realtime<7.0.0-27.27.1
7.0.0-27.27.1
ubuntu/linux-riscv<7.0.0-27.27.1
7.0.0-27.27.1
ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

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

    Fixed in 5.15.210
  2. Upgrade

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

    Fixed in 6.1.176
  3. Upgrade

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

    Fixed in 6.6.140
  4. Upgrade

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

    Fixed in 6.12.86
  5. Upgrade

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

    Fixed in 6.18.35
  6. Upgrade

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

    Fixed in 7.0.2
  7. 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 7.3.3-1
  8. Upgrade

    Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.124~20.04.1
  9. Upgrade

    Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1123.132~20.04.1
  10. Upgrade

    Upgrade ubuntu/linux-azure-fde-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1122.131~20.04.1
  11. Upgrade

    Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1118.128~20.04.1
  12. Upgrade

    Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-198.208~20.04.1
  13. Upgrade

    Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1111.115~20.04.1
  14. Upgrade

    Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.118~20.04.1
  15. Upgrade

    Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-195.205~20.04.1
  16. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1070.72~20.04.1
  17. Upgrade

    Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1114.120~20.04.1
  18. Upgrade

    Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1111.115~20.04.1
  19. Upgrade

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

    Fixed in 5.15.0-198.208
  20. Upgrade

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

    Fixed in 5.15.0-1117.124
  21. Upgrade

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

    Fixed in 6.8.0-1061.64~22.04.1
  22. Upgrade

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

    Fixed in 5.15.0-1123.132
  23. Upgrade

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

    Fixed in 6.8.0-1063.71~22.04.1
  24. Upgrade

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

    Fixed in 5.15.0-1122.131
  25. Upgrade

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

    Fixed in 6.8.0-1062.69~22.04.1
  26. Upgrade

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

    Fixed in 5.15.0-1118.128
  27. Upgrade

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

    Fixed in 6.8.0-1064.72~22.04.1
  28. Upgrade

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

    Fixed in 5.15.0-1113.119
  29. Upgrade

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

    Fixed in 5.15.0-1100.108
  30. Upgrade

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

    Fixed in 6.8.0-136.136~22.04.1
  31. Upgrade

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

    Fixed in 5.15.0-1111.115
  32. Upgrade

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

    Fixed in 6.8.0-1061.62~22.04.1
  33. Upgrade

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

    Fixed in 5.15.0-1112.118
  34. Upgrade

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

    Fixed in 5.15.0-1109.114
  35. Upgrade

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

    Fixed in 5.15.0-195.205
  36. Upgrade

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

    Fixed in 6.8.0-136.136.2~22.04.1
  37. Upgrade

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

    Fixed in 5.15.0-1112.113
  38. Upgrade

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

    Fixed in 6.8.0-1059.62~22.04.1
  39. Upgrade

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

    Fixed in 5.15.0-1070.72
  40. Upgrade

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

    Fixed in 5.15.0-1059.59
  41. Upgrade

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

    Fixed in 5.15.0-1114.120
  42. Upgrade

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

    Fixed in 6.8.0-1058.61~22.04.1
  43. Upgrade

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

    Fixed in 5.15.0-1113.116
  44. Upgrade

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

    Fixed in 6.8.0-136.136~22.04.3
  45. Upgrade

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

    Fixed in 5.15.0-1080.84
  46. Upgrade

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

    Fixed in 5.15.0-1101.103
  47. Upgrade

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

    Fixed in 5.15.0-1109.111
  48. Upgrade

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

    Fixed in 5.15.0-1116.125
  49. Upgrade

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

    Fixed in 6.8.1-1056.57~22.04.2
  50. Upgrade

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

    Fixed in 5.15.0-1117.124+fips1
  51. Upgrade

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

    Fixed in 5.15.0-1123.132+fips1
  52. Upgrade

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

    Fixed in 5.15.0-198.208+fips1
  53. Upgrade

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

    Fixed in 5.15.0-1118.128+fips1
  54. Upgrade

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

    Fixed in 6.8.0-136.136
  55. Upgrade

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

    Fixed in 6.8.0-1061.64
  56. Upgrade

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

    Fixed in 6.8.0-1063.71
  57. Upgrade

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

    Fixed in 6.8.0-1062.69
  58. Upgrade

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

    Fixed in 6.8.0-1064.72
  59. Upgrade

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

    Fixed in 6.8.0-1059.67
  60. Upgrade

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

    Fixed in 6.8.0-1046.50
  61. Upgrade

    Upgrade ubuntu/linux-hwe-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-28.28~24.04.1
  62. Upgrade

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

    Fixed in 6.8.0-1061.62
  63. Upgrade

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

    Fixed in 6.8.0-136.136.2
  64. Upgrade

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

    Fixed in 6.8.0-1059.62
  65. Upgrade

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

    Fixed in 6.8.0-1059.62.1
  66. Upgrade

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

    Fixed in 6.8.0-1030.31
  67. Upgrade

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

    Fixed in 6.8.0-1058.61
  68. Upgrade

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

    Fixed in 6.8.0-1061.65
  69. Upgrade

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

    Fixed in 6.8.0-1008.8
  70. Upgrade

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

    Fixed in 6.8.0-1033.34
  71. Upgrade

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

    Fixed in 6.8.0-1028.33
  72. Upgrade

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

    Fixed in 6.8.0-2050.52
  73. Upgrade

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

    Fixed in 6.8.1-1056.57
  74. Upgrade

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

    Fixed in 6.8.0-1061.64+fips1
  75. Upgrade

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

    Fixed in 6.8.0-1063.71+fips2
  76. Upgrade

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

    Fixed in 6.8.0-136.136+fips2
  77. Upgrade

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

    Fixed in 6.8.0-1064.72+fips1
  78. Upgrade

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

    Fixed in 7.0.0-27.27
  79. Upgrade

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

    Fixed in 7.0.0-1008.8
  80. Upgrade

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

    Fixed in 7.0.0-1010.10
  81. Upgrade

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

    Fixed in 7.0.0-1009.9
  82. Upgrade

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

    Fixed in 7.0.0-1007.7
  83. Upgrade

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

    Fixed in 7.0.0-1009.9
  84. Upgrade

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

    Fixed in 7.0.0-1013.13
  85. Upgrade

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

    Fixed in 7.0.0-1007.7
  86. Upgrade

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

    Fixed in 7.0.0-1014.14
  87. Upgrade

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

    Fixed in 7.0.0-27.27.1
  88. Upgrade

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

    Fixed in 7.0.0-27.27.1
  89. Compensating control

    Factor DACL structural checks into validate_dacl(), validate each ACE against the DACL bounds, and use the shared validator before the chmod/chown rebuild paths (including build_sec_desc(), id_mode_to_cifs_acl(), replace_sids_and_copy_aces(), and set_chmod_dacl()); reuse it in parse_dacl() so read-side parsing and write-side rewriting agree on well-formed DACLs.

Event History

May 1, 2026
CVE Published
via MITRE·01:56 PM
Data Sourced
via MITRE·01:56 PM
DescriptionSeverity
Data Sourced
via OSV·01:56 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·02:16 PM
RemedyDescriptionSeverityWeaknessAffected Software
Data Sourced
via Red Hat·03:08 PM
DescriptionSeverityAffected 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-2026-31709?

CVE-2026-31709 has been classified with a high severity rating due to potential exploitation risks in the Linux kernel.

2

How do I fix CVE-2026-31709?

To fix CVE-2026-31709, it is recommended to update to the latest patched version of the Linux kernel provided by The Linux Foundation.

3

What systems are affected by CVE-2026-31709?

CVE-2026-31709 affects various versions of the Linux kernel, specifically those that implement CIFS file system features.

4

What does CVE-2026-31709 impact?

CVE-2026-31709 impacts the functionality of the CIFS client by allowing improper validation of DACL, which could lead to unauthorized access.

5

Is there a workaround for CVE-2026-31709?

Currently, the most effective workaround for CVE-2026-31709 is to disable the CIFS protocol until an appropriate patch is applied.

Company

Resources

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