Vulnerability · Published Apr 20, 2026 · Assigned by Linux
CVE-2026-31430X.509: Fix out-of-bounds access when parsing extensions
High 7.1
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 0.1% (higher than 0% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
In the Linux kernel, the following vulnerability has been resolved: X.509: Fix out-of-bounds access when parsing extensions Leo reports an out-of-bounds access when parsing a certificate with empty Basic Constraints or Key Usage extension because the first byte of the extension is read before checking its length. Fix it. The bug can be triggered by an unprivileged user by submitting a specially crafted certificate to the kernel through the keyrings(7) API. Leo has demonstrated this with a proof-of-concept program responsibly disclosed off-list.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | linux | 6.12.85-1 | DEBIAN-CVE-2026-31430 |
| Debian:14 | linux | 6.19.13-1 | DEBIAN-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux | 6.8.0-136.136 | UBUNTU-CVE-2026-31430 |
| Ubuntu:25.10 | linux | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-allwinner-5.19 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-aws | 6.8.0-1061.64 | UBUNTU-CVE-2026-31430 |
| Ubuntu:25.10 | linux-aws | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-aws-5.19 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-aws-6.14 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-aws-6.17 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-aws-6.2 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-aws-6.5 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-aws-6.8 | 6.8.0-1061.64~22.04.1 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-azure | 6.8.0-1063.71 | UBUNTU-CVE-2026-31430 |
| Ubuntu:25.10 | linux-azure | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-azure-5.19 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-azure-6.11 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-azure-6.14 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-azure-6.17 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-azure-6.2 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-azure-6.5 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-azure-6.8 | 6.8.0-1063.71~22.04.1 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-azure-fde | 6.8.0-1062.69 | UBUNTU-CVE-2026-31430 |
| Ubuntu:25.10 | linux-azure-fde | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-azure-fde-5.19 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-azure-fde-6.14 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-azure-fde-6.2 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-azure-fde-6.8 | 6.8.0-1062.69~22.04.1 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-azure-nvidia | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-azure-nvidia-6.14 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-gcp | 6.8.0-1064.72 | UBUNTU-CVE-2026-31430 |
| Ubuntu:25.10 | linux-gcp | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-gcp-5.19 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-gcp-6.11 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-gcp-6.14 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-gcp-6.17 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-gcp-6.2 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-gcp-6.5 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-gcp-6.8 | 6.8.0-1064.72~22.04.1 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-gke | 6.8.0-1059.67 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-gkeop | 6.8.0-1046.50 | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-hwe-5.19 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-hwe-6.11 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-hwe-6.14 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-hwe-6.17 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-hwe-6.2 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-hwe-6.5 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-hwe-6.8 | 6.8.0-136.136~22.04.1 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-ibm | 6.8.0-1061.62 | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-ibm-6.8 | 6.8.0-1061.62~22.04.1 | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-lowlatency | 6.8.0-136.136.2 | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-5.19 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-lowlatency-hwe-6.11 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.2 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.5 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.8 | 6.8.0-136.136.2~22.04.1 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-nvidia | 6.8.0-1059.62 | UBUNTU-CVE-2026-31430 |
| Ubuntu:26.04:LTS | linux-nvidia | 7.0.0-1006.6 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-nvidia-6.11 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-nvidia-6.17 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-nvidia-6.2 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-nvidia-6.5 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-nvidia-6.8 | 6.8.0-1059.62~22.04.1 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-nvidia-lowlatency | 6.8.0-1059.62.1 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-nvidia-tegra | 6.8.0-1030.31 | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-oem-5.17 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-oem-6.0 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-oem-6.1 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-oem-6.11 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-oem-6.14 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-oem-6.17 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-oem-6.5 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-oem-6.8 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-oracle | 6.8.0-1058.61 | UBUNTU-CVE-2026-31430 |
| Ubuntu:25.10 | linux-oracle | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-oracle-6.14 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-oracle-6.17 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-oracle-6.5 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-oracle-6.8 | 6.8.0-1058.61~22.04.1 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-raspi | 6.8.0-1061.65 | UBUNTU-CVE-2026-31430 |
| Ubuntu:25.10 | linux-raspi | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:25.10 | linux-realtime | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:25.10 | linux-riscv | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-riscv-5.19 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-riscv-6.14 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-riscv-6.17 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-riscv-6.5 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-riscv-6.8 | 6.8.0-136.136~22.04.3 | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-starfive-5.19 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-starfive-6.2 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:22.04:LTS | linux-starfive-6.5 | no fix listed | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-vmware | 6.8.0-1008.8 | UBUNTU-CVE-2026-31430 |
| Ubuntu:24.04:LTS | linux-xilinx | 6.8.0-1033.34 | UBUNTU-CVE-2026-31430 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | 30eae2b037af54b24109dcaea21db46f6285c69b – before 672b526def1f94c1be8eb11b885b803da0d8c2f130eae2b037af54b24109dcaea21db46f6285c69b – before 30ab358fad0c7daa1d282ec48089901b21b36a2030eae2b037af54b24109dcaea21db46f6285c69b – before 206121294b9cf27f0589857f80d64f87e496ffb230eae2b037af54b24109dcaea21db46f6285c69b – before 7fb4dadc2734f4020d7543d688b8d49c8e569c6130eae2b037af54b24109dcaea21db46f6285c69b – before d702c3408213bb12bd570bb97204d8340d141c51 |
| Linux | Linux | 6.4 |
References
- https://git.kernel.org/stable/c/672b526def1f94c1be8eb11b885b803da0d8c2f1
- https://git.kernel.org/stable/c/30ab358fad0c7daa1d282ec48089901b21b36a20
- https://git.kernel.org/stable/c/206121294b9cf27f0589857f80d64f87e496ffb2
- https://git.kernel.org/stable/c/7fb4dadc2734f4020d7543d688b8d49c8e569c61
- https://git.kernel.org/stable/c/d702c3408213bb12bd570bb97204d8340d141c51