CVE-2026-63898: USB: serial: mct_u232: fix memory corruption with small endpoint

Q: What access does an attacker need to exploit this issue?

The vulnerability is rated as locally exploitable and requires low privileges. It does not require user interaction.

Q: What kind of device behavior triggers the flaw?

A malicious USB device can report a bulk-out endpoint maximum packet size smaller than the driver expects. If the driver increases the transfer size despite that smaller value, slab memory corruption can occur.

Q: What is the potential impact of successful exploitation?

The issue can cause slab corruption in the kernel. The supplied severity vector rates confidentiality, integrity, and availability impacts as high.

Published Jul 19, 2026

Updated

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

USB: serial: mctu232: fix memory corruption with small endpoint

The driver overrides the maximum transfer size for a specific device which only accepts 16 byte packets for its 32 byte bulk-out endpoint.

Make sure to never increase the maximum transfer size to prevent slab corruption should a malicious device report a smaller endpoint max packet size than expected.

Affected Software

282 affected componentsFixes available

Linux Linux kernel

Linux Linux kernel>=2.6.12.1<5.10.259

Linux Linux kernel>=5.11<5.15.210

Linux Linux kernel>=5.16<6.1.176

Linux Linux kernel>=6.2<6.6.143

Linux Linux kernel>=6.7<6.12.94

Linux Linux kernel>=6.13<6.18.35

Linux Linux kernel>=6.19<7.0.12

Linux Linux kernel=2.6.12

Linux Linux kernel=2.6.12-rc2

Linux Linux kernel=2.6.12-rc3

Linux Linux kernel=2.6.12-rc4

Linux Linux kernel=2.6.12-rc5

Linux Linux kernel=7.1-rc1

Linux Linux kernel=7.1-rc2

Linux Linux kernel=7.1-rc3

Linux Linux kernel=7.1-rc4

Linux Linux kernel=7.1-rc5

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-azure*

ubuntu/linux-lts-xenial*

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-aws-hwe*

ubuntu/linux-azure*

ubuntu/linux-gcp*

ubuntu/linux-hwe*

ubuntu/linux-hwe-edge*

ubuntu/linux-kvm*

ubuntu/linux-oracle*

ubuntu/linux-fips*

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-aws-5.4*

ubuntu/linux-azure*

ubuntu/linux-azure-4.15*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-5.4*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-4.15*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gcp-5.4*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-hwe-5.4*

ubuntu/linux-hwe-edge*

ubuntu/linux-ibm-5.4*

ubuntu/linux-kvm*

ubuntu/linux-oem*

ubuntu/linux-oracle*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-oracle-5.4*

ubuntu/linux-raspi-5.4*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux*

ubuntu/linux-aws*

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*

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-bluefield*

ubuntu/linux-gcp*

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*

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-iot*

ubuntu/linux-kvm*

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*

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle*

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-raspi*

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-xilinx-zynqmp*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

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<6.8.0-1066.69~22.04.1

6.8.0-1066.69~22.04.1

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<6.8.0-1070.78~22.04.1

6.8.0-1070.78~22.04.1

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<6.8.0-1068.75~22.04.1

6.8.0-1068.75~22.04.1

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<6.8.0-1070.78~22.04.1

6.8.0-1070.78~22.04.1

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-ibm<5.15.0-1111.115

5.15.0-1111.115

ubuntu/linux-ibm-6.8<6.8.0-1066.67~22.04.1

6.8.0-1066.67~22.04.1

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<6.8.0-146.146.1~22.04.1

6.8.0-146.146.1~22.04.1

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<6.8.0-1064.67~22.04.1

6.8.0-1064.67~22.04.1

ubuntu/linux-nvidia-tegra*

ubuntu/linux-nvidia-tegra-igx*

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*

ubuntu/linux-raspi*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8<6.8.0-146.146~22.04.1

6.8.0-146.146~22.04.1

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp<5.15.0-1080.84

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<6.8.1-1061.62~22.04.1

6.8.1-1061.62~22.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1117.124+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<6.8.0-146.146

6.8.0-146.146

ubuntu/linux-aws<6.8.0-1066.69

6.8.0-1066.69

ubuntu/linux-aws-6.14*

ubuntu/linux-aws-6.17*

ubuntu/linux-azure<6.8.0-1070.78

6.8.0-1070.78

ubuntu/linux-azure-6.11*

ubuntu/linux-azure-6.14*

ubuntu/linux-azure-6.17*

ubuntu/linux-azure-7.0<7.0.0-1014.14~24.04.1

7.0.0-1014.14~24.04.1

ubuntu/linux-azure-fde<6.8.0-1068.75

6.8.0-1068.75

ubuntu/linux-azure-fde-6.14*

ubuntu/linux-azure-fde-6.17*

ubuntu/linux-azure-fde-7.0<7.0.0-1013.13~24.04.1

7.0.0-1013.13~24.04.1

ubuntu/linux-azure-nvidia*

ubuntu/linux-azure-nvidia-6.14*

ubuntu/linux-gcp<6.8.0-1070.78

6.8.0-1070.78

ubuntu/linux-gcp-6.11*

ubuntu/linux-gcp-6.14*

ubuntu/linux-gcp-7.0<7.0.0-1011.11~24.04.1

7.0.0-1011.11~24.04.1

ubuntu/linux-gke<6.8.0-1065.73

6.8.0-1065.73

ubuntu/linux-gkeop<6.8.0-1051.55

6.8.0-1051.55

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<6.8.0-1066.67

6.8.0-1066.67

ubuntu/linux-lowlatency<6.8.0-146.146.1

6.8.0-146.146.1

ubuntu/linux-lowlatency-hwe-6.11*

ubuntu/linux-nvidia<6.8.0-1064.67

6.8.0-1064.67

ubuntu/linux-nvidia-6.11*

ubuntu/linux-nvidia-6.17*

ubuntu/linux-nvidia-7.0<7.0.0-1016.16~24.04.1

7.0.0-1016.16~24.04.1

ubuntu/linux-nvidia-lowlatency<6.8.0-1064.67.1

6.8.0-1064.67.1

ubuntu/linux-nvidia-tegra*

ubuntu/linux-oem-6.11*

ubuntu/linux-oem-6.14*

ubuntu/linux-oem-6.17*

ubuntu/linux-oem-6.8*

ubuntu/linux-oracle<6.8.0-1063.66

6.8.0-1063.66

ubuntu/linux-oracle-6.14*

ubuntu/linux-oracle-6.17*

ubuntu/linux-oracle-7.0<7.0.0-1011.11~24.04.1

7.0.0-1011.11~24.04.1

ubuntu/linux-raspi*

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-6.14*

ubuntu/linux-riscv-6.17*

ubuntu/linux-riscv-7.0<7.0.0-28.28.1~24.04.3

7.0.0-28.28.1~24.04.3

ubuntu/linux-xilinx*

ubuntu/linux-bluefield<6.8.0-1032.37

6.8.0-1032.37

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime<6.8.1-1061.62

6.8.1-1061.62

ubuntu/linux-realtime-6.14*

ubuntu/linux-realtime-6.17*

ubuntu/linux-aws-fips<6.8.0-1066.69+fips1

6.8.0-1066.69+fips1

ubuntu/linux-azure-fips<6.8.0-1069.77+fips1

6.8.0-1069.77+fips1

ubuntu/linux-fips<6.8.0-146.146+fips1

6.8.0-146.146+fips1

ubuntu/linux-gcp-fips<6.8.0-1070.78+fips1

6.8.0-1070.78+fips1

ubuntu/linux<7.0.0-28.28

7.0.0-28.28

ubuntu/linux-aws<7.0.0-1009.9

7.0.0-1009.9

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<7.0.0-1008.8

7.0.0-1008.8

ubuntu/linux-gke<7.0.0-1003.4

7.0.0-1003.4

ubuntu/linux-ibm<7.0.0-1010.10

7.0.0-1010.10

ubuntu/linux-nvidia<7.0.0-1016.16

7.0.0-1016.16

ubuntu/linux-nvidia-bos<7.0.0-2016.16

7.0.0-2016.16

ubuntu/linux-oem-7.0<7.0.0-1009.9

7.0.0-1009.9

ubuntu/linux-oracle<7.0.0-1008.8

7.0.0-1008.8

ubuntu/linux-raspi<7.0.0-1015.15

7.0.0-1015.15

ubuntu/linux-realtime<7.0.0-28.28.1

7.0.0-28.28.1

ubuntu/linux-riscv<7.0.0-28.28.1

7.0.0-28.28.1

debian/linux<6.1.176-1

6.1.176-1

debian/linux<6.12.94-1

6.12.94-1

debian/linux<7.0.12-1

7.0.12-1

linux/kernel>=2.6.12<5.10.259

5.10.259

linux/kernel>=5.11.0<5.15.210

5.15.210

linux/kernel>=5.16.0<6.1.176

6.1.176

linux/kernel>=6.2.0<6.6.143

6.6.143

linux/kernel>=6.7.0<6.12.94

6.12.94

linux/kernel>=6.13.0<6.18.35

6.18.35

linux/kernel>=6.19.0<7.0.12

7.0.12

debian/linux

6.1.176-16.1.190-16.12.107-16.12.115-27.2.12-17.2.15-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1117.124~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1123.132~20.04.1
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
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1118.128~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-198.208~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1111.115~20.04.1
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
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
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1114.120~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1111.115~20.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-198.208
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1117.124
Upgrade
Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1066.69~22.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1123.132
Upgrade
Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1070.78~22.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 5.15.0-1122.131
Upgrade
Upgrade ubuntu/linux-azure-fde-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1068.75~22.04.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1118.128
Upgrade
Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1070.78~22.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1113.119
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1100.108
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1111.115
Upgrade
Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1066.67~22.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1112.118
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1109.114
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-195.205
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-146.146.1~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1112.113
Upgrade
Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1064.67~22.04.1
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1114.120
Upgrade
Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-146.146~22.04.1
Upgrade
Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.84
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1101.103
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1109.111
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1116.125
Upgrade
Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.1-1061.62~22.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1117.124+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1123.132+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-198.208+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1118.128+fips1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 6.8.0-146.146
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 6.8.0-1066.69
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 6.8.0-1070.78
Upgrade
Upgrade ubuntu/linux-azure-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1014.14~24.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 6.8.0-1068.75
Upgrade
Upgrade ubuntu/linux-azure-fde-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1013.13~24.04.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 6.8.0-1070.78
Upgrade
Upgrade ubuntu/linux-gcp-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1011.11~24.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 6.8.0-1065.73
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 6.8.0-1051.55
Upgrade
Upgrade ubuntu/linux-hwe-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-28.28~24.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 6.8.0-1066.67
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-146.146.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1064.67
Upgrade
Upgrade ubuntu/linux-nvidia-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1016.16~24.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-1064.67.1
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 6.8.0-1063.66
Upgrade
Upgrade ubuntu/linux-oracle-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1011.11~24.04.1
Upgrade
Upgrade ubuntu/linux-riscv-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-28.28.1~24.04.3
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 6.8.0-1032.37
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 6.8.1-1061.62
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-1066.69+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-1069.77+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-146.146+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-1070.78+fips1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 7.0.0-28.28
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 7.0.0-1009.9
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 7.0.0-1010.10
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 7.0.0-1009.9
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 7.0.0-1008.8
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 7.0.0-1003.4
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 7.0.0-1010.10
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 7.0.0-1016.16
Upgrade
Upgrade ubuntu/linux-nvidia-bos to a version that resolves this vulnerability.
Fixed in 7.0.0-2016.16
Upgrade
Upgrade ubuntu/linux-oem-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1009.9
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 7.0.0-1008.8
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 7.0.0-1015.15
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 7.0.0-28.28.1
Upgrade
Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.
Fixed in 7.0.0-28.28.1
Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 6.1.176-1
Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 6.12.94-1
Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 7.0.12-1
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 6.12.113-1Fixed in 7.2.12-1Fixed in 7.2.14-1
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 5.10.259
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 5.15.210
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 6.1.176
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 6.6.143
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 6.12.94
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 6.18.35
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 7.0.12
Compensating control
Modify the USB serial mct_u232 driver to never increase the maximum transfer size, preventing slab corruption when a device reports a smaller endpoint maximum packet size than expected.

Event History

Jul 19, 2026

CVE Published

via MITRE·02:55 PM

Data Sourced

via MITRE·02:55 PM

Description

Data Sourced

via OSV·02:55 PM

DescriptionAffected Software

Data Sourced

via NVD·04:17 PM

RemedyDescriptionSeverityWeaknessAffected Software

Data Sourced

via OSV·04:17 PM

Severity

Frequently Asked Questions

What access does an attacker need to exploit this issue?

The vulnerability is rated as locally exploitable and requires low privileges. It does not require user interaction.

What kind of device behavior triggers the flaw?

A malicious USB device can report a bulk-out endpoint maximum packet size smaller than the driver expects. If the driver increases the transfer size despite that smaller value, slab memory corruption can occur.

What is the potential impact of successful exploitation?

The issue can cause slab corruption in the kernel. The supplied severity vector rates confidentiality, integrity, and availability impacts as high.

CVE-2026-63898: USB: serial: mct_u232: fix memory corruption with small endpoint

Affected Software

Remediation

Event History

Frequently Asked Questions

What access does an attacker need to exploit this issue?

What kind of device behavior triggers the flaw?

What is the potential impact of successful exploitation?

Company

Resources

Contact