🛡️ CVE-2026-43403 on Ubuntu — linux
Description
In the Linux kernel, the following vulnerability has been resolved: nsfs: tighten permission checks for ns iteration ioctls Even privileged services should not necessarily be able to see other privileged service's namespaces so they can't leak information to each other. Use may_see_all_namespaces() helper that centralizes this policy until the nstree adapts.
Distribution advisory
This page covers CVE-2026-43403 as tracked by Ubuntu, for the package linux. No fixed version has been recorded for this distribution yet.
How this vulnerability can be exploited
This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity high, availability high.
Affected software
UBUNTU-CVE-2026-43403 is recorded against 158 packages.
- linux
- linux-allwinner-5.19
- linux-aws
- linux-aws-5.0
- linux-aws-5.11
- linux-aws-5.13
- linux-aws-5.15
- linux-aws-5.19
- linux-aws-5.3
- linux-aws-5.4
- linux-aws-5.8
- linux-aws-6.14
- linux-aws-6.17
- linux-aws-6.2
- linux-aws-6.5
- linux-aws-6.8
- linux-aws-fips
- linux-aws-hwe
- linux-azure
- linux-azure-4.15
- linux-azure-5.11
- linux-azure-5.13
- linux-azure-5.15
- linux-azure-5.19
Show the remaining 134 packages
- linux-azure-5.3
- linux-azure-5.4
- linux-azure-5.8
- linux-azure-6.11
- linux-azure-6.14
- linux-azure-6.17
- linux-azure-6.2
- linux-azure-6.5
- linux-azure-6.8
- linux-azure-edge
- linux-azure-fde
- linux-azure-fde-5.15
- linux-azure-fde-5.19
- linux-azure-fde-6.14
- linux-azure-fde-6.17
- linux-azure-fde-6.2
- linux-azure-fde-6.8
- linux-azure-fips
- linux-azure-nvidia
- linux-azure-nvidia-6.14
- linux-bluefield
- linux-fips
- linux-gcp
- linux-gcp-4.15
- linux-gcp-5.11
- linux-gcp-5.13
- linux-gcp-5.15
- linux-gcp-5.19
- linux-gcp-5.3
- linux-gcp-5.4
- linux-gcp-5.8
- linux-gcp-6.11
- linux-gcp-6.14
- linux-gcp-6.17
- linux-gcp-6.2
- linux-gcp-6.5
- linux-gcp-6.8
- linux-gcp-fips
- linux-gke
- linux-gke-4.15
- linux-gke-5.15
- linux-gke-5.4
- linux-gkeop
- linux-gkeop-5.15
- linux-gkeop-5.4
- linux-hwe
- linux-hwe-5.11
- linux-hwe-5.13
- linux-hwe-5.15
- linux-hwe-5.19
- linux-hwe-5.4
- linux-hwe-5.8
- linux-hwe-6.11
- linux-hwe-6.14
- linux-hwe-6.17
- linux-hwe-6.2
- linux-hwe-6.5
- linux-hwe-6.8
- linux-hwe-edge
- linux-ibm
- linux-ibm-5.15
- linux-ibm-5.4
- linux-ibm-6.8
- linux-intel-5.13
- linux-intel-iot-realtime
- linux-intel-iotg
- linux-intel-iotg-5.15
- linux-iot
- linux-kvm
- linux-lowlatency
- linux-lowlatency-hwe-5.15
- linux-lowlatency-hwe-5.19
- linux-lowlatency-hwe-6.11
- linux-lowlatency-hwe-6.2
- linux-lowlatency-hwe-6.5
- linux-lowlatency-hwe-6.8
- linux-lts-xenial
- linux-nvidia
- linux-nvidia-6.11
- linux-nvidia-6.17
- linux-nvidia-6.2
- linux-nvidia-6.5
- linux-nvidia-6.8
- linux-nvidia-lowlatency
- linux-nvidia-tegra
- linux-nvidia-tegra-5.15
- linux-nvidia-tegra-igx
- linux-oem
- linux-oem-5.10
- linux-oem-5.13
- linux-oem-5.14
- linux-oem-5.17
- linux-oem-5.6
- linux-oem-6.0
- linux-oem-6.1
- linux-oem-6.11
- linux-oem-6.14
- linux-oem-6.17
- linux-oem-6.5
- linux-oem-6.8
- linux-oracle
- linux-oracle-5.0
- linux-oracle-5.11
- linux-oracle-5.13
- linux-oracle-5.15
- linux-oracle-5.3
- linux-oracle-5.4
- linux-oracle-5.8
- linux-oracle-6.14
- linux-oracle-6.17
- linux-oracle-6.5
- linux-oracle-6.8
- linux-raspi
- linux-raspi-5.4
- linux-raspi-realtime
- linux-raspi2
- linux-realtime
- linux-realtime-6.14
- linux-realtime-6.17
- linux-realtime-6.8
- linux-riscv
- linux-riscv-5.11
- linux-riscv-5.15
- linux-riscv-5.19
- linux-riscv-5.8
- linux-riscv-6.14
- linux-riscv-6.17
- linux-riscv-6.5
- linux-riscv-6.8
- linux-starfive-5.19
- linux-starfive-6.2
- linux-starfive-6.5
- linux-xilinx
- linux-xilinx-zynqmp
Timeline and source
Published on 8 May 2026 and last revised on 11 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
ubuntu.com (Report)
www.cve.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
CVE-2026-43403 on other distributions
Each distribution ships its own build and its own fixed version. Pick the one you run:
Details
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| linux | — | — |
| linux-allwinner-5.19 | — | — |
| linux-aws | — | — |
| linux-aws-5.0 | — | — |
| linux-aws-5.11 | — | — |
| linux-aws-5.13 | — | — |
| linux-aws-5.15 | — | — |
| linux-aws-5.19 | — | — |
| linux-aws-5.3 | — | — |
| linux-aws-5.4 | — | — |
| linux-aws-5.8 | — | — |
| linux-aws-6.14 | — | — |
| linux-aws-6.17 | — | — |
| linux-aws-6.2 | — | — |
| linux-aws-6.5 | — | — |
| linux-aws-6.8 | — | — |
| linux-aws-fips | — | — |
| linux-aws-hwe | — | — |
| linux-azure | — | — |
| linux-azure-4.15 | — | — |
| linux-azure-5.11 | — | — |
| linux-azure-5.13 | — | — |
| linux-azure-5.15 | — | — |
| linux-azure-5.19 | — | — |
| linux-azure-5.3 | — | — |
| linux-azure-5.4 | — | — |
| linux-azure-5.8 | — | — |
| linux-azure-6.11 | — | — |
| linux-azure-6.14 | — | — |
| linux-azure-6.17 | — | — |
| linux-azure-6.2 | — | — |
| linux-azure-6.5 | — | — |
| linux-azure-6.8 | — | — |
| linux-azure-edge | — | — |
| linux-azure-fde | — | — |
| linux-azure-fde-5.15 | — | — |
| linux-azure-fde-5.19 | — | — |
| linux-azure-fde-6.14 | — | — |
| linux-azure-fde-6.17 | — | — |
| linux-azure-fde-6.2 | — | — |
| linux-azure-fde-6.8 | — | — |
| linux-azure-fips | — | — |
| linux-azure-nvidia | — | — |
| linux-azure-nvidia-6.14 | — | — |
| linux-bluefield | — | — |
| linux-fips | — | — |
| linux-gcp | — | — |
| linux-gcp-4.15 | — | — |
| linux-gcp-5.11 | — | — |
| linux-gcp-5.13 | — | — |
| linux-gcp-5.15 | — | — |
| linux-gcp-5.19 | — | — |
| linux-gcp-5.3 | — | — |
| linux-gcp-5.4 | — | — |
| linux-gcp-5.8 | — | — |
| linux-gcp-6.11 | — | — |
| linux-gcp-6.14 | — | — |
| linux-gcp-6.17 | — | — |
| linux-gcp-6.2 | — | — |
| linux-gcp-6.5 | — | — |
| linux-gcp-6.8 | — | — |
| linux-gcp-fips | — | — |
| linux-gke | — | — |
| linux-gke-4.15 | — | — |
| linux-gke-5.15 | — | — |
| linux-gke-5.4 | — | — |
| linux-gkeop | — | — |
| linux-gkeop-5.15 | — | — |
| linux-gkeop-5.4 | — | — |
| linux-hwe | — | — |
| linux-hwe-5.11 | — | — |
| linux-hwe-5.13 | — | — |
| linux-hwe-5.15 | — | — |
| linux-hwe-5.19 | — | — |
| linux-hwe-5.4 | — | — |
| linux-hwe-5.8 | — | — |
| linux-hwe-6.11 | — | — |
| linux-hwe-6.14 | — | — |
| linux-hwe-6.17 | — | — |
| linux-hwe-6.2 | — | — |
| linux-hwe-6.5 | — | — |
| linux-hwe-6.8 | — | — |
| linux-hwe-edge | — | — |
| linux-ibm | — | — |
| linux-ibm-5.15 | — | — |
| linux-ibm-5.4 | — | — |
| linux-ibm-6.8 | — | — |
| linux-intel-5.13 | — | — |
| linux-intel-iot-realtime | — | — |
| linux-intel-iotg | — | — |
| linux-intel-iotg-5.15 | — | — |
| linux-iot | — | — |
| linux-kvm | — | — |
| linux-lowlatency | — | — |
| linux-lowlatency-hwe-5.15 | — | — |
| linux-lowlatency-hwe-5.19 | — | — |
| linux-lowlatency-hwe-6.11 | — | — |
| linux-lowlatency-hwe-6.2 | — | — |
| linux-lowlatency-hwe-6.5 | — | — |
| linux-lowlatency-hwe-6.8 | — | — |
| linux-lts-xenial | — | — |
| linux-nvidia | — | — |
| linux-nvidia-6.11 | — | — |
| linux-nvidia-6.17 | — | — |
| linux-nvidia-6.2 | — | — |
| linux-nvidia-6.5 | — | — |
| linux-nvidia-6.8 | — | — |
| linux-nvidia-lowlatency | — | — |
| linux-nvidia-tegra | — | — |
| linux-nvidia-tegra-5.15 | — | — |
| linux-nvidia-tegra-igx | — | — |
| linux-oem | — | — |
| linux-oem-5.10 | — | — |
| linux-oem-5.13 | — | — |
| linux-oem-5.14 | — | — |
| linux-oem-5.17 | — | — |
| linux-oem-5.6 | — | — |
| linux-oem-6.0 | — | — |
| linux-oem-6.1 | — | — |
| linux-oem-6.11 | — | — |
| linux-oem-6.14 | — | — |
| linux-oem-6.17 | — | — |
| linux-oem-6.5 | — | — |
| linux-oem-6.8 | — | — |
| linux-oracle | — | — |
| linux-oracle-5.0 | — | — |
| linux-oracle-5.11 | — | — |
| linux-oracle-5.13 | — | — |
| linux-oracle-5.15 | — | — |
| linux-oracle-5.3 | — | — |
| linux-oracle-5.4 | — | — |
| linux-oracle-5.8 | — | — |
| linux-oracle-6.14 | — | — |
| linux-oracle-6.17 | — | — |
| linux-oracle-6.5 | — | — |
| linux-oracle-6.8 | — | — |
| linux-raspi | — | — |
| linux-raspi-5.4 | — | — |
| linux-raspi-realtime | — | — |
| linux-raspi2 | — | — |
| linux-realtime | — | — |
| linux-realtime-6.14 | — | — |
| linux-realtime-6.17 | — | — |
| linux-realtime-6.8 | — | — |
| linux-riscv | — | — |
| linux-riscv-5.11 | — | — |
| linux-riscv-5.15 | — | — |
| linux-riscv-5.19 | — | — |
| linux-riscv-5.8 | — | — |
| linux-riscv-6.14 | — | — |
| linux-riscv-6.17 | — | — |
| linux-riscv-6.5 | — | — |
| linux-riscv-6.8 | — | — |
| linux-starfive-5.19 | — | — |
| linux-starfive-6.2 | — | — |
| linux-starfive-6.5 | — | — |
| linux-xilinx | — | — |
| linux-xilinx-zynqmp | — | — |
References
Similar Threats
- Unknown CGA-23jx-hhcx-m389
- Unknown CGA-2qp7-6757-fmgc
- Unknown CGA-2rj5-jc55-r267
- Unknown CGA-3m96-cwq8-6xmx
- Unknown CGA-3qj9-973w-fh9g
Site Security Check
Is linux part of your stack?
UBUNTU-CVE-2026-43403 is rated CVSS 8.8 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.
Scan My Site Free →No credit card required · Results in minutes
ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.
