Home Assistant OS 18.5 patches Raspberry Pi IPv4 kernel flaw

Home Assistant OS 18.5 updates Raspberry Pi and Home Assistant Yellow to Linux 6.18.59, fixing CVE-2026-98432; other supported boards were already patched in 18.4.

Quick summary: Home Assistant OS 18.5 became the latest stable release on 6 November 2026. It updates the Linux kernel to 6.18.59 on Raspberry Pi 3, 4 and 5 systems and Home Assistant YellowPriceAliExpress price, fixing CVE-2026-98432 in the IPv4 networking stack. Other supported boards received the same security fix with Home Assistant OS 18.4.

Home Assistant has issued OS 18.5 as a narrowly focused Raspberry Pi security release. This is an operating-system update, separate from the feature changes in Home Assistant Core 2026.11, and its main purpose is to move the Raspberry Pi kernel to a patched build.

Top view of a Raspberry Pi 4 board, illustrating the Home Assistant OS 18.5 security update
Illustrative Raspberry Pi 4; the photograph does not show Home Assistant OS or Home Assistant YellowAliExpress price. Photo by Vishnu Mohanan on Unsplash, used under the Unsplash License.

Which installations need Home Assistant OS 18.5?

InstallationUpdate position
Raspberry Pi 3, 4 or 5 running Home Assistant OSInstall OS 18.5 to receive Linux 6.18.59
Home Assistant YellowAliExpress priceInstall OS 18.5; Yellow uses the Raspberry Pi kernel line
Other Home Assistant OS boards and generic targetsHome Assistant says the security correction was already included with the kernel update in OS 18.4
Home Assistant Container or Core on another Linux distributionOS 18.5 does not update the host; follow that distribution’s kernel security updates

The distinction is useful because Home Assistant OS version numbers describe the managed appliance operating system. They are not the same as the monthly Home Assistant application release. A Raspberry Pi running Container on Raspberry Pi OS, for example, gets its kernel from Raspberry Pi OS rather than from Home Assistant OS.

What CVE-2026-98432 affects

The corrected vulnerability is a use-after-free error in the Linux kernel’s handling of IPv4 socket options. A use-after-free occurs when software continues to reference memory after it should have been released, potentially leading to a crash or unintended code execution under the right conditions.

Home Assistant’s release note says the project is not aware of widespread exploitation in the wild. It nevertheless specifically encourages users to update systems that are directly exposed to the internet or connected to untrusted networks. That wording is important: the release is a real security fix, but the project is not claiming an active mass-exploitation campaign.

A kernel-only follow-up to OS 18.4

For Raspberry Pi and Yellow, OS 18.5 updates Linux from the earlier 6.18.58 line to 6.18.59. The release does not bundle a new Home Assistant feature set. Its changelog is deliberately short, covering the kernel update and a build-system change that again uses a single Linux patch directory for all boards.

The previous Home Assistant OS 18.4 stable release was broader: it fixed affected RTL8761B Bluetooth adapters, Raspberry Pi boot and USB-storage problems, a Realtek VLAN regression and several underlying components. The Raspberry Pi-specific 18.5 release exists because those targets still needed the newer kernel security fix.

What users should do

Home Assistant OS users can install 18.5 through the normal update panel after making or confirming a current backup. Systems on Raspberry Pi hardware or Home Assistant Yellow should show the OS update when their channel offers the stable build. After the reboot, the system information should report Home Assistant OS 18.5.

Users who previously delayed OS 18.4 because of Raspberry Pi storage or network concerns can review the changes covered in the earlier 18.4 release-candidate report and the final 18.4 notes. OS 18.5 is free and Home Assistant has not announced any hardware or subscription change alongside it.

Sources

CONTINUE EXPLORING / SMART HOME & ESPHOME

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