Vulnerability · Published Sep 17, 2026 · Assigned by Linux
CVE-2026-90231apparmor: fix unconfined user namespace restriction forced stack
High 8.4
In plain English
A high-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
In the Linux kernel, the following vulnerability has been resolved: apparmor: fix unconfined user namespace restriction forced stack If a task is already confined by a stack the unprivileged transition restriction on unconfined is not correctly, applied. This results in an escape if two transitions through an unconfined profile can be executed. Fix this by pushing the check into the per profile label build. The check will always be done against unconfined and result in a stack of just the unconfined component when necessary.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | linux | 6.12.115-2 | DEBIAN-CVE-2026-90231 |
| Debian:14 | linux | 7.2.6-1 | DEBIAN-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux | 7.0.0-42.42 | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-allwinner-5.19 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-aws | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-aws | 7.0.0-1016.17 | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-aws-5.19 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-aws-6.14 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-aws-6.17 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-aws-6.2 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-aws-6.5 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-aws-6.8 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-aws-7.0 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-azure | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-azure | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-azure-5.19 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-azure-6.11 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-azure-6.14 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-azure-6.17 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-azure-6.2 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-azure-6.5 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-azure-6.8 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-azure-7.0 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-azure-fde | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-azure-fde | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-azure-fde-5.19 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-azure-fde-6.14 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-azure-fde-6.17 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-azure-fde-6.2 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-azure-fde-6.8 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-azure-fde-7.0 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-azure-nvidia | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-azure-nvidia-6.14 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-gcp | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-gcp | 7.0.0-1016.18 | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-gcp-5.19 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-gcp-6.11 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-gcp-6.14 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-gcp-6.17 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-gcp-6.2 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-gcp-6.5 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-gcp-6.8 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-gcp-7.0 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-gke | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-gke | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-gkeop | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-hwe-5.19 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-hwe-6.11 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-hwe-6.14 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-hwe-6.17 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-hwe-6.2 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-hwe-6.5 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-hwe-6.8 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-hwe-7.0 | 7.0.0-42.42~24.04.1 | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-ibm | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-ibm | 7.0.0-1017.17 | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-ibm-6.8 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-lowlatency | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-5.19 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-lowlatency-hwe-6.11 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.2 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.5 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.8 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-nvidia | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-nvidia | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-nvidia-6.11 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-nvidia-6.17 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-nvidia-6.2 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-nvidia-6.5 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-nvidia-6.8 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-nvidia-7.0 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-nvidia-bos | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-nvidia-lowlatency | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-nvidia-tegra | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-oem-5.17 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-oem-6.0 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-oem-6.1 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-oem-6.11 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-oem-6.14 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-oem-6.17 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-oem-6.5 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-oem-6.8 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-oem-7.0 | 7.0.0-1017.17 | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-oracle | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-oracle | 7.0.0-1015.16 | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-oracle-6.14 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-oracle-6.17 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-oracle-6.5 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-oracle-6.8 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-oracle-7.0 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-raspi | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-raspi | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:26.04:LTS | linux-riscv | 7.0.0-42.42.1 | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-riscv-5.19 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-riscv-6.14 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-riscv-6.17 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-riscv-6.5 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-riscv-6.8 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-riscv-7.0 | 7.0.0-42.42.1~24.04.1 | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-starfive-5.19 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-starfive-6.2 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:22.04:LTS | linux-starfive-6.5 | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-vmware | no fix listed | UBUNTU-CVE-2026-90231 |
| Ubuntu:24.04:LTS | linux-xilinx | no fix listed | UBUNTU-CVE-2026-90231 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | 2d9da9b188b8cd3b579d7ef5ba5d334be9dd38fc – before fdd341654471cae4fbd9635d32b848cd0c8bc4372d9da9b188b8cd3b579d7ef5ba5d334be9dd38fc – before 7d1099b86356df81c379159bfb8a598aaf83ce812d9da9b188b8cd3b579d7ef5ba5d334be9dd38fc – before 7da0bdf0610f6d35bbb061536a47fc41646306f02d9da9b188b8cd3b579d7ef5ba5d334be9dd38fc – before 08c2f7c8d4b1434cfae006f3daf4d1bce330b57b |
| Linux | Linux | 6.7 |