Linux Kernel Incorrect Resource Transfer Between Spheres Vulnerability
Linux Kernel contains an incorrect resource transfer between spheres vulnerability that could allow for privilege escalation.
Quick answer
Linux Kernel should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- Review vendor advisory for affected versions.
Fixed versions
- Apply the latest vendor-supported patched version.
How to fix it
CVE-2026-31431 is a Linux kernel privilege escalation issue in the crypto algif_aead path. Apply the kernel update provided by the Linux distribution or vendor and reboot into the fixed kernel. If a patch is not yet available for a specific host, reduce local attack opportunities by restricting shell access, limiting untrusted workloads, and applying vendor-approved temporary mitigations until the fixed kernel is deployed.
- Inventory Linux hosts, containers with host access, WSL environments, and appliances that depend on the affected kernel code path.
- Apply the kernel security update from the distribution vendor or appliance vendor for CVE-2026-31431.
- Reboot each host into the fixed kernel and remove or deprioritize vulnerable old kernels where operationally safe.
- Restrict local shell access and untrusted multi-user workloads until patching is complete.
- Apply vendor-approved temporary mitigations for AF_ALG or algif_aead exposure only when patching cannot happen immediately.
- Review sudoers, setuid binaries, new root-owned files, cron jobs, systemd units, and authentication logs for signs of local privilege escalation.
- Prioritize shared hosting, CI runners, container hosts, bastions, and systems where untrusted users can execute code.
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Verify the fix
- Confirm uname -r and the package manager show the fixed kernel version from the distribution vendor.
- Verify the system has rebooted into the updated kernel and is not still running the vulnerable kernel in memory.
- Confirm no untrusted local users or workloads can access vulnerable hosts before patch completion.
- Review integrity and auth logs for suspicious privilege escalation indicators.
- Run a Fixnx scan for public Linux-hosted services after the maintenance window.
Related categories
Trusted references
FAQ
What is affected by CVE-2026-31431?
Linux Kernel should be checked against the vendor advisory and trusted references linked on this page.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
Why can this risk appear in multiple categories?
A vulnerability can belong to more than one platform or ecosystem. Fixnx keeps one canonical risk page while also listing it in every relevant category.