CVE-2026-31430

Updated on 20 Apr 2026

Severity

7.1 High severity

Details

CVSS score
7.1

Overview

About vulnerability

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. A flaw was found in the Linux kernel. An unprivileged user can exploit this vulnerability by submitting a specially crafted X.509 certificate to the kernel through the keyrings(7) application programming interface (API). This certificate, specifically when containing empty Basic Constraints or Key Usage extensions, can trigger an out-of-bounds access during parsing. An out-of-bounds access is a memory corruption issue where a program attempts to read or write data beyond the allocated memory region, which can lead to system instability or a denial of service.

Details

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Debian 13 Planned
Ubuntu 24.04 Planned