UBUNTU-CVE-2026-23403: Medium severity ubuntu/linux vulnerability

Q: Which Ubuntu kernel package variants are listed as affected?

The listed software includes ubuntu/linux, ubuntu/linux-fips, ubuntu/linux-aws, ubuntu/linux-azure, ubuntu/linux-aws-fips, ubuntu/linux-azure-fips, ubuntu/linux-gcp, and ubuntu/linux-gcp-fips.

Q: What level of access does exploitation require?

The CVSS vector indicates local access and low privileges are required. No user interaction is required.

Q: What is the expected security impact?

The CVSS vector indicates a high availability impact, with no stated confidentiality or integrity impact. The issue involves a memory leak while unpacking multiple profiles and can also disrupt namespace consistency checking.

Published Apr 1, 2026

Updated

In the Linux kernel, the following vulnerability has been resolved: apparmor: fix memory leak in verifyheader The function sets ns = NULL on every call, leaking the namespace string allocated in previous iterations when multiple profiles are unpacked. This also breaks namespace consistency checking since ns is always NULL when the comparison is made. Remove the incorrect assignment. The caller (aaunpack) initializes ns to NULL once before the loop, which is sufficient.

Affected Software

242 affected componentsFixes available

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-azure<4.15.0-1200.215~14.04.1

4.15.0-1200.215~14.04.1

ubuntu/linux-lts-xenial*

ubuntu/linux-aws-hwe<4.15.0-1191.204~16.04.1

4.15.0-1191.204~16.04.1

ubuntu/linux-azure<4.15.0-1200.215~16.04.1

4.15.0-1200.215~16.04.1

ubuntu/linux-gcp<4.15.0-1184.201~16.04.1

4.15.0-1184.201~16.04.1

ubuntu/linux-hwe<4.15.0-249.261~16.04.1

4.15.0-249.261~16.04.1

ubuntu/linux-oracle<4.15.0-1153.164~16.04.1

4.15.0-1153.164~16.04.1

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-hwe-edge*

ubuntu/linux-kvm*

ubuntu/linux-fips*

ubuntu/linux<4.15.0-249.261

4.15.0-249.261

ubuntu/linux-aws<4.15.0-1191.204

4.15.0-1191.204

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-aws-5.4<5.4.0-1156.166~18.04.1

5.4.0-1156.166~18.04.1

ubuntu/linux-azure*

ubuntu/linux-azure-4.15<4.15.0-1200.215

4.15.0-1200.215

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-5.4<5.4.0-1161.167~18.04.1

5.4.0-1161.167~18.04.1

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-4.15<4.15.0-1184.201

4.15.0-1184.201

ubuntu/linux-gcp-5.3*

ubuntu/linux-gcp-5.4<5.4.0-1159.168~18.04.1

5.4.0-1159.168~18.04.1

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-hwe-5.4<5.4.0-227.247~18.04.1

5.4.0-227.247~18.04.1

ubuntu/linux-hwe-edge*

ubuntu/linux-ibm-5.4<5.4.0-1102.107~18.04.1

5.4.0-1102.107~18.04.1

ubuntu/linux-kvm<4.15.0-1173.178

4.15.0-1173.178

ubuntu/linux-oem*

ubuntu/linux-oracle<4.15.0-1153.164

4.15.0-1153.164

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-oracle-5.4<5.4.0-1154.164~18.04.1

5.4.0-1154.164~18.04.1

ubuntu/linux-raspi-5.4<5.4.0-1139.152~18.04.1

5.4.0-1139.152~18.04.1

ubuntu/linux-aws-fips<4.15.0-2129.135

4.15.0-2129.135

ubuntu/linux-azure-fips<4.15.0-2109.115

4.15.0-2109.115

ubuntu/linux-fips<4.15.0-1146.158

4.15.0-1146.158

ubuntu/linux-gcp-fips<4.15.0-2092.98

4.15.0-2092.98

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux<5.4.0-227.247

5.4.0-227.247

ubuntu/linux-aws<5.4.0-1156.166

5.4.0-1156.166

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.15<5.15.0-1103.110~20.04.1

5.15.0-1103.110~20.04.1

ubuntu/linux-aws-5.8*

ubuntu/linux-azure<5.4.0-1160.166

5.4.0-1160.166

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.15<5.15.0-1110.119~20.04.1

5.15.0-1110.119~20.04.1

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-bluefield<5.4.0-1116.123

5.4.0-1116.123

ubuntu/linux-gcp<5.4.0-1159.168

5.4.0-1159.168

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

ubuntu/linux-gcp-5.15<5.15.0-1103.112~20.04.1

5.15.0-1103.112~20.04.1

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<5.15.0-173.183~20.04.1

5.15.0-173.183~20.04.1

ubuntu/linux-hwe-5.8*

ubuntu/linux-ibm<5.4.0-1102.107

5.4.0-1102.107

ubuntu/linux-ibm-5.15<5.15.0-1097.100~20.04.1

5.15.0-1097.100~20.04.1

ubuntu/linux-intel-5.13*

ubuntu/linux-intel-iotg-5.15<5.15.0-1098.104~20.04.1

5.15.0-1098.104~20.04.1

ubuntu/linux-iot<5.4.0-1060.63

5.4.0-1060.63

ubuntu/linux-kvm<5.4.0-1143.152

5.4.0-1143.152

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-173.183~20.04.1

5.15.0-173.183~20.04.1

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1055.55~20.04.1

5.15.0-1055.55~20.04.1

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle<5.4.0-1154.164

5.4.0-1154.164

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.15<5.15.0-1100.106~20.04.1

5.15.0-1100.106~20.04.1

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi<5.4.0-1139.152

5.4.0-1139.152

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.15<5.15.0-1098.102~20.04.1

5.15.0-1098.102~20.04.1

ubuntu/linux-riscv-5.8*

ubuntu/linux-xilinx-zynqmp<5.4.0-1074.78

5.4.0-1074.78

ubuntu/linux-aws-fips<5.4.0-1156.166+fips1

5.4.0-1156.166+fips1

ubuntu/linux-azure-fips<5.4.0-1160.166+fips1

5.4.0-1160.166+fips1

ubuntu/linux-fips<5.4.0-1130.140

5.4.0-1130.140

ubuntu/linux-gcp-fips<5.4.0-1159.168+fips1

5.4.0-1159.168+fips1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux<5.15.0-173.183

5.15.0-173.183

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1103.110

5.15.0-1103.110

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8<6.8.0-1050.53~22.04.1

6.8.0-1050.53~22.04.1

ubuntu/linux-azure<5.15.0-1109.118

5.15.0-1109.118

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-6.8<6.8.0-1051.57~22.04.1

6.8.0-1051.57~22.04.1

ubuntu/linux-azure-fde<5.15.0-1109.118.1

5.15.0-1109.118.1

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<5.15.0-1103.112

5.15.0-1103.112

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gcp-6.8<6.8.0-1052.55~22.04.1

6.8.0-1052.55~22.04.1

ubuntu/linux-gke<5.15.0-1099.105

5.15.0-1099.105

ubuntu/linux-gkeop<5.15.0-1086.94

5.15.0-1086.94

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-hwe-6.8<6.8.0-106.106~22.04.1

6.8.0-106.106~22.04.1

ubuntu/linux-ibm<5.15.0-1097.100

5.15.0-1097.100

ubuntu/linux-ibm-6.8<6.8.0-1049.49~22.04.1

6.8.0-1049.49~22.04.1

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-intel-iotg<5.15.0-1098.104

5.15.0-1098.104

ubuntu/linux-kvm<5.15.0-1095.100

5.15.0-1095.100

ubuntu/linux-lowlatency<5.15.0-173.183

5.15.0-173.183

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-lowlatency-hwe-6.8<6.8.0-106.106.1~22.04.1

6.8.0-106.106.1~22.04.1

ubuntu/linux-nvidia<5.15.0-1098.99

5.15.0-1098.99

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8<6.8.0-1049.52~22.04.1

6.8.0-1049.52~22.04.1

ubuntu/linux-nvidia-tegra<5.15.0-1055.55

5.15.0-1055.55

ubuntu/linux-nvidia-tegra-igx<5.15.0-1044.44

5.15.0-1044.44

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1100.106

5.15.0-1100.106

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8<6.8.0-1047.48~22.04.1

6.8.0-1047.48~22.04.1

ubuntu/linux-raspi<5.15.0-1097.100

5.15.0-1097.100

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8<6.8.0-106.106~22.04.1

6.8.0-106.106~22.04.1

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp<5.15.0-1067.71

5.15.0-1067.71

ubuntu/linux-bluefield<5.15.0-1087.89

5.15.0-1087.89

ubuntu/linux-intel-iot-realtime<5.15.0-1096.98

5.15.0-1096.98

ubuntu/linux-realtime<5.15.0-1102.111

5.15.0-1102.111

ubuntu/linux-realtime-6.8<6.8.1-1045.46~22.04.1

6.8.1-1045.46~22.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1103.110+fips1

5.15.0-1103.110+fips1

ubuntu/linux-azure-fips<5.15.0-1109.118+fips1

5.15.0-1109.118+fips1

ubuntu/linux-fips<5.15.0-173.183+fips1

5.15.0-173.183+fips1

ubuntu/linux-gcp-fips<5.15.0-1103.112+fips1

5.15.0-1103.112+fips1

ubuntu/linux<6.8.0-106.106

6.8.0-106.106

ubuntu/linux-aws<6.8.0-1050.53

6.8.0-1050.53

ubuntu/linux-aws-6.14*

ubuntu/linux-aws-6.17<6.17.0-1009.9~24.04.2

6.17.0-1009.9~24.04.2

ubuntu/linux-azure<6.8.0-1051.57

6.8.0-1051.57

ubuntu/linux-azure-6.11*

ubuntu/linux-azure-6.14*

ubuntu/linux-azure-6.17<6.17.0-1010.10~24.04.1

6.17.0-1010.10~24.04.1

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<6.8.0-1052.55

6.8.0-1052.55

ubuntu/linux-gcp-6.11*

ubuntu/linux-gcp-6.14*

ubuntu/linux-gcp-6.17<6.17.0-1009.9~24.04.3

6.17.0-1009.9~24.04.3

ubuntu/linux-gke<6.8.0-1048.53

6.8.0-1048.53

ubuntu/linux-gkeop<6.8.0-1035.38

6.8.0-1035.38

ubuntu/linux-hwe-6.11*

ubuntu/linux-hwe-6.14*

ubuntu/linux-hwe-6.17<6.17.0-19.19~24.04.2

6.17.0-19.19~24.04.2

ubuntu/linux-ibm<6.8.0-1049.49

6.8.0-1049.49

ubuntu/linux-lowlatency<6.8.0-106.106.1

6.8.0-106.106.1

ubuntu/linux-lowlatency-hwe-6.11*

ubuntu/linux-nvidia<6.8.0-1049.52

6.8.0-1049.52

ubuntu/linux-nvidia-6.11*

ubuntu/linux-nvidia-6.17<6.17.0-1014.14

6.17.0-1014.14

ubuntu/linux-nvidia-lowlatency<6.8.0-1049.52.1

6.8.0-1049.52.1

ubuntu/linux-nvidia-tegra<6.8.0-1020.20

6.8.0-1020.20

ubuntu/linux-oem-6.11*

ubuntu/linux-oem-6.14*

ubuntu/linux-oem-6.17<6.17.0-1017.17

6.17.0-1017.17

ubuntu/linux-oem-6.8*

ubuntu/linux-oracle<6.8.0-1047.48

6.8.0-1047.48

ubuntu/linux-oracle-6.14*

ubuntu/linux-oracle-6.17<6.17.0-1009.9~24.04.1

6.17.0-1009.9~24.04.1

ubuntu/linux-raspi<6.8.0-1050.54

6.8.0-1050.54

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-6.14*

ubuntu/linux-riscv-6.17<6.17.0-19.19.1~24.04.1

6.17.0-19.19.1~24.04.1

ubuntu/linux-xilinx<6.8.0-1028.29

6.8.0-1028.29

ubuntu/linux-bluefield<6.8.0-1017.21

6.8.0-1017.21

ubuntu/linux-raspi-realtime<6.8.0-2040.41

6.8.0-2040.41

ubuntu/linux-realtime<6.8.1-1045.46

6.8.1-1045.46

ubuntu/linux-realtime-6.14*

ubuntu/linux-realtime-6.17<6.17.0-1008.9~24.04.1

6.17.0-1008.9~24.04.1

ubuntu/linux-aws-fips<6.8.0-1050.53+fips1

6.8.0-1050.53+fips1

ubuntu/linux-azure-fips<6.8.0-1052.58+fips1

6.8.0-1052.58+fips1

ubuntu/linux-fips<6.8.0-106.106+fips1

6.8.0-106.106+fips1

ubuntu/linux-gcp-fips<6.8.0-1052.55+fips1

6.8.0-1052.55+fips1

ubuntu/linux<6.17.0-19.19

6.17.0-19.19

ubuntu/linux-aws<6.17.0-1009.9

6.17.0-1009.9

ubuntu/linux-azure<6.17.0-1010.10

6.17.0-1010.10

ubuntu/linux-azure-fde*

ubuntu/linux-gcp<6.17.0-1009.9

6.17.0-1009.9

ubuntu/linux-oracle<6.17.0-1009.9

6.17.0-1009.9

ubuntu/linux-raspi<6.17.0-1010.10

6.17.0-1010.10

ubuntu/linux-realtime<6.17.0-1008.9

6.17.0-1008.9

ubuntu/linux-riscv<6.17.0-19.19.1

6.17.0-19.19.1

ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 4.15.0-1200.215~14.04.1
Upgrade
Upgrade ubuntu/linux-aws-hwe to a version that resolves this vulnerability.
Fixed in 4.15.0-1191.204~16.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 4.15.0-1200.215~16.04.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 4.15.0-1184.201~16.04.1
Upgrade
Upgrade ubuntu/linux-hwe to a version that resolves this vulnerability.
Fixed in 4.15.0-249.261~16.04.1
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 4.15.0-1153.164~16.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 4.15.0-249.261
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 4.15.0-1191.204
Upgrade
Upgrade ubuntu/linux-aws-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1156.166~18.04.1
Upgrade
Upgrade ubuntu/linux-azure-4.15 to a version that resolves this vulnerability.
Fixed in 4.15.0-1200.215
Upgrade
Upgrade ubuntu/linux-azure-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1161.167~18.04.1
Upgrade
Upgrade ubuntu/linux-gcp-4.15 to a version that resolves this vulnerability.
Fixed in 4.15.0-1184.201
Upgrade
Upgrade ubuntu/linux-gcp-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1159.168~18.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-227.247~18.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1102.107~18.04.1
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 4.15.0-1173.178
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 4.15.0-1153.164
Upgrade
Upgrade ubuntu/linux-oracle-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1154.164~18.04.1
Upgrade
Upgrade ubuntu/linux-raspi-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1139.152~18.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-2129.135
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-2109.115
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-1146.158
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-2092.98
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.4.0-227.247
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.4.0-1156.166
Upgrade
Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1103.110~20.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.4.0-1160.166
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1110.119~20.04.1
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.4.0-1116.123
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.4.0-1159.168
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1103.112~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-173.183~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.4.0-1102.107
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1097.100~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1098.104~20.04.1
Upgrade
Upgrade ubuntu/linux-iot to a version that resolves this vulnerability.
Fixed in 5.4.0-1060.63
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.4.0-1143.152
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-173.183~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1055.55~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.4.0-1154.164
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1100.106~20.04.1
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.4.0-1139.152
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1098.102~20.04.1
Upgrade
Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.
Fixed in 5.4.0-1074.78
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.4.0-1156.166+fips1
Upgrade
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Fixed in 5.4.0-1160.166+fips1
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Fixed in 5.4.0-1130.140
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Fixed in 5.4.0-1159.168+fips1
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Fixed in 5.15.0-173.183
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Fixed in 5.15.0-1103.110
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Fixed in 6.8.0-1050.53~22.04.1
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Fixed in 5.15.0-1109.118
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Fixed in 6.8.0-1051.57~22.04.1
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Fixed in 5.15.0-1109.118.1
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Fixed in 6.8.0-1058.65~22.04.1
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Fixed in 5.15.0-1103.112
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Fixed in 6.8.0-1052.55~22.04.1
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Fixed in 5.15.0-1099.105
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Fixed in 5.15.0-1086.94
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Fixed in 6.8.0-106.106~22.04.1
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Fixed in 5.15.0-1097.100
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Fixed in 6.8.0-1049.49~22.04.1
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Fixed in 5.15.0-1098.104
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Fixed in 5.15.0-1095.100
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Fixed in 5.15.0-173.183
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Fixed in 6.8.0-106.106.1~22.04.1
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Fixed in 5.15.0-1098.99
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Fixed in 6.8.0-1049.52~22.04.1
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Fixed in 5.15.0-1055.55
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Fixed in 5.15.0-1044.44
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Fixed in 5.15.0-1100.106
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Fixed in 6.8.0-1047.48~22.04.1
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Fixed in 5.15.0-1097.100
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Fixed in 6.8.0-106.106~22.04.1
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Fixed in 5.15.0-1067.71
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Fixed in 5.15.0-1087.89
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Fixed in 5.15.0-1096.98
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Fixed in 5.15.0-1102.111
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Fixed in 6.8.1-1045.46~22.04.1
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Fixed in 5.15.0-1103.110+fips1
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Fixed in 5.15.0-1109.118+fips1
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Fixed in 5.15.0-173.183+fips1
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Fixed in 5.15.0-1103.112+fips1
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Fixed in 6.8.0-106.106
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Fixed in 6.8.0-1050.53
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Fixed in 6.17.0-1009.9~24.04.2
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Fixed in 6.8.0-1051.57
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Fixed in 6.17.0-1010.10~24.04.1
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Fixed in 6.8.0-1058.65
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Fixed in 6.8.0-1039.42
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Fixed in 6.8.0-1052.55
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Fixed in 6.17.0-1009.9~24.04.3
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Fixed in 6.8.0-1048.53
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Fixed in 6.8.0-1035.38
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Fixed in 6.17.0-19.19~24.04.2
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Fixed in 6.8.0-1049.49
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Fixed in 6.8.0-106.106.1
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Fixed in 6.8.0-1049.52
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Fixed in 6.17.0-1014.14
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Fixed in 6.8.0-1049.52.1
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Fixed in 6.8.0-1020.20
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Fixed in 6.17.0-1017.17
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Fixed in 6.8.0-1047.48
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Fixed in 6.17.0-1009.9~24.04.1
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Fixed in 6.8.0-1050.54
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Fixed in 6.17.0-19.19.1~24.04.1
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Fixed in 6.8.0-1028.29
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Fixed in 6.8.0-1017.21
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Fixed in 6.8.0-2040.41
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Fixed in 6.8.1-1045.46
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Fixed in 6.17.0-1008.9~24.04.1
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Fixed in 6.8.0-1050.53+fips1
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Fixed in 6.8.0-1052.58+fips1
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Fixed in 6.8.0-106.106+fips1
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Fixed in 6.8.0-1052.55+fips1
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Fixed in 6.17.0-19.19
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Fixed in 6.17.0-1009.9
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Fixed in 6.17.0-1010.10
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Fixed in 6.17.0-1009.9
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Fixed in 6.17.0-1009.9
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Fixed in 6.17.0-1010.10
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Fixed in 6.17.0-1008.9
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Fixed in 6.17.0-19.19.1
Configuration
Remove the incorrect `*ns = NULL` assignment from `verify_header`; retain the caller-side initialization in `aa_unpack` before the loop.
Linux kernel AppArmor verify_header namespace initialization = initialize *ns to NULL once before the unpacking loop, not on every call

Event History

Apr 1, 2026

CVE Published

via OSV·09:16 AM

Data Sourced

via OSV·09:16 AM

DescriptionSeverityAffected Software

Frequently Asked Questions

Which Ubuntu kernel package variants are listed as affected?

The listed software includes ubuntu/linux, ubuntu/linux-fips, ubuntu/linux-aws, ubuntu/linux-azure, ubuntu/linux-aws-fips, ubuntu/linux-azure-fips, ubuntu/linux-gcp, and ubuntu/linux-gcp-fips.

What level of access does exploitation require?

The CVSS vector indicates local access and low privileges are required. No user interaction is required.

What is the expected security impact?

The CVSS vector indicates a high availability impact, with no stated confidentiality or integrity impact. The issue involves a memory leak while unpacking multiple profiles and can also disrupt namespace consistency checking.

UBUNTU-CVE-2026-23403: Medium severity ubuntu/linux vulnerability

Affected Software

Remediation

Event History

Frequently Asked Questions

Which Ubuntu kernel package variants are listed as affected?

What level of access does exploitation require?

What is the expected security impact?

Company

Resources

Contact

Frequently Asked Questions

Which Ubuntu kernel package variants are listed as affected?

What level of access does exploitation require?

What is the expected security impact?