Linux Kernel Privilege Escalation CVE-2026-31431 Draws Patch and PoC Activity
CVE-2026-31431 is a Linux kernel flaw classified as CWE-669: Incorrect Resource Transfer Between Spheres that can enable local privilege escalation to root and, in some cases, bypass isolation boundaries. The Canadian Centre for Cyber Security warned that the impact becomes more severe when the bug is chained with a remote code execution vulnerability, and urged organizations to identify exposed systems, apply vendor fixes, reboot after kernel updates, restrict access, enforce kernel security controls, monitor logs, and segment high-risk or Internet-facing workloads.
Vendor and community activity indicates broad exposure across modern Linux platforms. Red Hat lists RHEL 8, RHEL 9, RHEL 10, and corresponding kernel-rt packages as affected, while RHEL 6 and RHEL 7 are marked not affected because the vulnerable code is absent. Public exploit interest accelerated after Theori published the "Copy Fail" technical write-up and proof-of-concept repository, which references testing on Ubuntu 24.04 LTS, Amazon Linux 2023, RHEL 10.1, and SUSE 16; Rocky Linux also published related errata, signaling downstream patch availability in enterprise Linux ecosystems.
Timeline
Apr 30, 2026
Canada issues national alert on Linux vulnerability CVE-2026-31431
The Canadian Centre for Cyber Security published Alert AL26-009 warning that CVE-2026-31431 could enable privilege escalation to root or bypass isolation mechanisms on vulnerable Linux systems. The alert stressed higher risk when chained with remote code execution and urged organizations to identify affected systems, apply patches, reboot, and harden exposed workloads.
Apr 29, 2026
Public PoC and technical write-up for CVE-2026-31431 released
A GitHub repository by theori-io published a technical write-up and proof-of-concept exploit for 'Copy Fail' (CVE-2026-31431), including exploit code and tested kernel/distribution details. The repository quickly drew broad public attention, indicating active security community interest in exploitation details.
Jan 5, 2026
Red Hat lists OpenShift 4 rhcos as affected by CVE-2026-31431
Red Hat's CVE page identifies Red Hat OpenShift Container Platform 4 rhcos as affected by CVE-2026-31431, expanding the known impact beyond the RHEL kernel packages already noted. The same page continues to mark RHEL 6, RHEL 7, and RHEL 7 kernel-rt as not affected because the vulnerable code is not present.
Jan 5, 2026
Red Hat marks RHEL 8, 9, and 10 kernel packages as affected
Red Hat's product impact matrix for CVE-2026-31431 states that RHEL 8, RHEL 8 kernel-rt, RHEL 9, RHEL 9 kernel-rt, and RHEL 10 kernel are affected, while RHEL 6, RHEL 7, and RHEL 7 kernel-rt are not affected because the vulnerable code is not present.
Jan 5, 2026
Rocky Linux publishes errata for CVE-2026-31431
Rocky Linux issued product errata RLSA-2026:12265 and RLSA-2026:12271 related to CVE-2026-31431, indicating vendor remediation activity for affected systems.
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