Description
An issue was discovered in the Linux kernel before 6.3.4. fs/ksmbd/smb2pdu.c in ksmbd does not properly check the UserName value because it does not consider the address of security buffer, leading to an out-of-bounds read.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.3.7-1 | — |
| Debian 13 | linux | 6.3.7-1 | — |
| Debian 12 | linux | 6.1.37-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1023.25 | — |
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-83.92 | USN-6339-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1044.49 | USN-6350-1 |
| Ubuntu 22.04 LTS | linux-aws-6.2 | 6.2.0-1011.11~22.04.1 | USN-6338-1 |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1046.53 | USN-6339-3 |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1046.53.1 | USN-6339-3 |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1041.49 | USN-6339-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.2 | 6.2.0-1013.13~22.04.1 | USN-6338-2 |
| Ubuntu 22.04 LTS | linux-gke +1 | 5.15.0-1041.46 | USN-6351-1, USN-6339-1 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1027.32 | USN-6351-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.2 | 6.2.0-32.32~22.04.1 | USN-6338-1 |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1037.40 | USN-6339-3, USN-6339-1 |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1039.45 | USN-6339-4 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.2 | 6.2.0-1012.12~22.04.1 | USN-6338-1 |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1032.32 | USN-6339-1 |
| Ubuntu 22.04 LTS | linux-nvidia-6.2 | 6.2.0-1010.10 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1017.17 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1004.4 | — |
| Ubuntu 22.04 LTS | linux-oem-6.1 | 6.1.0-1016.16 | — |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1042.48 | USN-6350-1 |
| Ubuntu 22.04 LTS | linux-riscv +12 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1025.29 | — |
| Ubuntu 20.04 LTS | linux-aws-5.15 | 5.15.0-1044.49~20.04.1 | USN-6350-1 |
| Ubuntu 20.04 LTS | linux-azure-5.15 | 5.15.0-1046.53~20.04.1 | USN-6339-3 |
| Ubuntu 20.04 LTS | linux-azure-fde-5.15 | 5.15.0-1046.53~20.04.1.1 | USN-6339-3 |
| Ubuntu 20.04 LTS | linux-gcp-5.15 | 5.15.0-1041.49~20.04.1 | USN-6339-2 |
| Ubuntu 20.04 LTS | linux-gkeop-5.15 | 5.15.0-1027.32~20.04.1 | USN-6339-2 |
| Ubuntu 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-83.92~20.04.1 | USN-6339-1 |
| Ubuntu 20.04 LTS | linux-ibm-5.15 | 5.15.0-1037.40~20.04.1 | USN-6350-1 |
| Ubuntu 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1040.46~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1017.17~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-oracle-5.15 | 5.15.0-1042.48~20.04.1 | USN-6350-1 |
| Ubuntu 20.04 LTS | linux-riscv +24 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-riscv-5.15 | 5.15.0-1040.44~20.04.3 | — |
| Ubuntu 18.04 LTS | linux-gcp +13 | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1038.40 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1045.50 | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips | No fix yet | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | kernel | 5.15.122.1-2 | — |
Advisories 9
- USN-6338-1 linux, linux-aws, linux-aws-6.2, linux-hwe-6.2, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-6.2, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Oct 23, 2026
- USN-6338-2 linux-gcp, linux-gcp-6.2, linux-ibm, linux-oracle, linux-starfive vulnerabilities Ubuntu Security Notices (USN) · Oct 23, 2026
- USN-6339-1 linux, linux-gcp, linux-hwe-5.15, linux-ibm, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Oct 22, 2026
- USN-6339-3 linux-azure, linux-azure-5.15, linux-azure-fde, linux-azure-fde-5.15, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Oct 22, 2026
- USN-6350-1 linux-aws, linux-aws-5.15, linux-ibm-5.15, linux-oracle, linux-oracle-5.15 vulnerabilities Ubuntu Security Notices (USN) · Oct 22, 2026
- USN-6351-1 linux-gke, linux-gkeop vulnerabilities Ubuntu Security Notices (USN) · Oct 22, 2026
- USN-6339-2 linux-gcp-5.15, linux-gkeop-5.15 vulnerabilities Ubuntu Security Notices (USN) · Oct 22, 2026
- USN-6339-4 linux-intel-iotg vulnerabilities Ubuntu Security Notices (USN) · Oct 22, 2026
- WID-SEC-2023-1773 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 18, 2023