1. Ubuntu Security Notices
  2. USN-8440-1

USN-8440-1: Linux kernel (Azure) vulnerabilities

Publication date

16 June 2026

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

Details

Josh Eads, Kristoffer Janke, Eduardo Vela Nava, Tavis Ormandy, and Matteo
Rizzo discovered that some AMD Zen processors did not properly verify the
signature of CPU microcode. This flaw is known as EntrySign. A privileged
attacker could possibly use this issue to cause load malicious CPU
microcode causing loss of integrity and confidentiality. (CVE-2024-36347)

It was discovered that the Linux kernel algif_aead module did not properly
handle in-place cryptographic operations. This flaw is known as Copy Fail.
A local attacker could use this to escalate privileges, or possibly escape
a container. (CVE-2026-31431)

It was discovered that the Linux kernel did not properly handle shared page
fragments during socket buffer operations, collectively known as Dirty
Frag. A logic flaw existed in the XFRM ESP-in-TCP subsystem and in the
RxRPC networking...

Josh Eads, Kristoffer Janke, Eduardo Vela Nava, Tavis Ormandy, and Matteo
Rizzo discovered that some AMD Zen processors did not properly verify the
signature of CPU microcode. This flaw is known as EntrySign. A privileged
attacker could possibly use this issue to cause load malicious CPU
microcode causing loss of integrity and confidentiality. (CVE-2024-36347)

It was discovered that the Linux kernel algif_aead module did not properly
handle in-place cryptographic operations. This flaw is known as Copy Fail.
A local attacker could use this to escalate privileges, or possibly escape
a container. (CVE-2026-31431)

It was discovered that the Linux kernel did not properly handle shared page
fragments during socket buffer operations, collectively known as Dirty
Frag. A logic flaw existed in the XFRM ESP-in-TCP subsystem and in the
RxRPC networking subsystem when processing paged fragments. A local
attacker could use this to escalate privileges, or possibly escape a
container. (CVE-2026-43284, CVE-2026-43500, CVE-2026-45998, CVE-2026-46000)

It was discovered that a logic flaw existed in the XFRM ESP-in-TCP
subsystem in the Linux kernel when handling socket buffer fragments. This
flaw is known as Fragnesia. A local attacker could use this to escalate
privileges, or possibly escape a container. (CVE-2026-43503,
CVE-2026-46300)

Qualys discovered that a race condition existed in the ptrace subsystem of
the Linux kernel when privileged processes are exiting. An unprivileged
local attacker could use this issue to expose sensitive information.
(CVE-2026-46333)

Tristan Madani discovered that Ubuntu Linux kernel 6.8, 6.17 and 7.0
contain a memory leak when handling AppArmor notifications. A local
attacker could use this to cause resource exhaustion. (CVE-2026-47326)

Tristan Madani discovered that Ubuntu Linux kernel 6.8, 6.17 and 7.0
contain a NULL pointer dereference when handling AppArmor notifications. A
local attacker could use this to cause a kernel oops. (CVE-2026-47327)

Tristan Madani discovered that Ubuntu Linux kernel 6.8, 6.17 and 7.0
contained an invalid free when handling AppArmor notifications. A local
attacker could use this to corrupt kernel memory. (CVE-2026-47328)

Tristan Madani discovered that Ubuntu Linux kernel 6.8, 6.17 and 7.0
contained insufficient validation of AppArmor notification responses. A
local attacker could use this to allow crafted responses to be processed.
(CVE-2026-47329)

Tristan Madani discovered that Ubuntu Linux kernel 6.8, 6.17 and 7.0 used
an uninitialized variable when handling AppArmor notifications. A local
attacker could use this to cause incorrect caching of data.
(CVE-2026-47330)

Tristan Madani discovered that Ubuntu Linux kernel 6.8 contained a use-
after-free (UAF) bug. A local attacker could use this to cause memory
corruption and, theoretically, arbitrary code execution. (CVE-2026-47331)

Tristan Madani discovered that Ubuntu Linux kernel 6.8, 6.17 and 7.0
contained an out-of-bounds (OOB) read when handling AppArmor notifications.
A local attacker could use this to cause information disclosure of kernel
memory. (CVE-2026-47332)

Tristan Madani discovered that Ubuntu Linux kernel 6.8, 6.17 and 7.0
contained a out-of-bounds (OOB) read when handling AppArmor notifications.
A local attacker could use this to cause kernel memory corruption and,
theoretically, influence processing of AppArmor policies. (CVE-2026-47333)

Tristan Madani discovered that Ubuntu Linux kernel 6.8, 6.17 and 7.0
contained incorrect holding of locks when handling AppArmor notifications.
A local attacker could use this to cause a kernel panic or deadlock.
(CVE-2026-47334)

Tristan Madani discovered that Ubuntu Linux kernel 6.8 contained a NULL
pointer dereference when handling AppArmor notifications. A local attacker
could use this to cause a kernel panic. (CVE-2026-47335)

Tristan Madani discovered that Ubuntu Linux kernel 6.8 used an
uninitialized variable when handling AppArmor AF_INET/AF_INET6 socket
mediation. A local attacker could use this to influence processing of fine-
grained network socket mediation. (CVE-2026-47336)

Tristan Madani and Trevor Lawrence have each independently discovered that
Ubuntu Linux kernel 6.8, 6.17 and 7.0 contained a NULL pointer dereference
when handling AppArmor network socket mediation. A local attacker could use
this to cause a kernel oops. (CVE-2026-47337)

Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:

  • ARM64 architecture;
  • MIPS architecture;
  • PowerPC architecture;
  • x86 architecture;
  • Block layer subsystem;
  • Cryptographic API;
  • Compute Acceleration Framework;
  • ACPI drivers;
  • Drivers core;
  • Network block device driver;
  • Null block device driver;
  • Ublk userspace block driver;
  • Bluetooth drivers;
  • Character device driver;
  • TPM device driver;
  • Clock framework and drivers;
  • Data acquisition framework and drivers;
  • Counter interface drivers;
  • Hardware crypto device drivers;
  • DMA engine subsystem;
  • DPLL subsystem;
  • GPU drivers;
  • HID subsystem;
  • Hardware monitoring drivers;
  • Intel Trace Hub HW tracing drivers;
  • IIO ADC drivers;
  • IIO subsystem;
  • InfiniBand drivers;
  • Input Device core drivers;
  • On-Chip Interconnect management framework;
  • IOMMU subsystem;
  • IRQ chip drivers;
  • Modular ISDN driver;
  • LED subsystem;
  • Macintosh device drivers;
  • Multiple devices driver;
  • Media drivers;
  • UACCE accelerator framework;
  • MMC subsystem;
  • Ethernet bonding driver;
  • Network drivers;
  • Mellanox network drivers;
  • STMicroelectronics network drivers;
  • Ethernet team driver;
  • MediaTek network drivers;
  • NVME drivers;
  • PA-RISC drivers;
  • PHY drivers;
  • Chrome hardware platform drivers;
  • x86 platform drivers;
  • i.MX PM domains;
  • Voltage and Current Regulator drivers;
  • SCSI subsystem;
  • SLIMbus drivers;
  • SPI subsystem;
  • Media Oriented Systems Transport (MOST) driver;
  • Realtek RTL8723BS SDIO drivers;
  • TCM subsystem;
  • USB Host Controller drivers;
  • USB Type-C Connector System Software Interface driver;
  • Backlight driver;
  • W1 Dallas's 1-wire bus driver;
  • Watchdog drivers;
  • Xen hypervisor drivers;
  • BFS file system;
  • BTRFS file system;
  • EFI Variable file system;
  • exFAT file system;
  • Ext4 file system;
  • F2FS file system;
  • FUSE (File system in Userspace);
  • HFS+ file system;
  • File systems infrastructure;
  • Journaling layer for block devices (JBD2);
  • Network file system (NFS) client;
  • Network file system (NFS) server daemon;
  • File system notification infrastructure;
  • NTFS3 file system;
  • OCFS2 file system;
  • SMB network file system;
  • BPF subsystem;
  • Ethernet bridge;
  • Scheduler infrastructure;
  • Netfilter;
  • NFC subsystem;
  • Tracing infrastructure;
  • io_uring subsystem;
  • Perf events;
  • Locking primitives;
  • Shadow Call Stack mechanism;
  • Floating proportions library;
  • Memory management;
  • Bluetooth subsystem;
  • CAIF protocol;
  • CAN network layer;
  • Ceph Core library;
  • Networking core;
  • Ethtool driver;
  • Handshake API;
  • HSR network protocol;
  • IPv4 networking;
  • IPv6 networking;
  • L2TP protocol;
  • MAC80211 subsystem;
  • Multipath TCP;
  • NET/ROM layer;
  • Open vSwitch;
  • Packet sockets;
  • RDS protocol;
  • Rose network layer;
  • RxRPC session sockets;
  • Network traffic control;
  • SCTP protocol;
  • Network sockets;
  • Sun RPC protocol;
  • TLS protocol;
  • Unix domain sockets;
  • VMware vSockets driver;
  • Wireless networking;
  • Integrity Measurement Architecture(IMA) framework;
  • Key management;
  • Simplified Mandatory Access Control Kernel framework;
  • ALSA AC97 driver;
  • Generic PCM loopback sound driver;
  • FireWire sound drivers;
  • HD-audio driver;
  • Turtle Beach Wavefront ALSA driver;
  • Creative Sound Blaster X-Fi driver;
  • AMD SoC Alsa drivers;
  • Texas InstrumentS Audio (ASoC/HDA) drivers;
  • STMicroelectronics SoC drivers;
  • USB sound devices;
  • KVM subsystem

Update instructions

After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
22.04 LTS jammy linux-image-6.8.0-1059-azure –  6.8.0-1059.65~22.04.1
linux-image-azure –  6.8.0-1059.65~22.04.1
linux-image-azure-6.8 –  6.8.0-1059.65~22.04.1

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References

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