1. Ubuntu Security Notices
  2. USN-8393-1

USN-8393-1: Linux kernel (Azure FIPS) vulnerabilities

Publication date

4 June 2026

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

Details

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...

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;
  • x86 architecture;
  • Cryptographic API;
  • Compute Acceleration Framework;
  • Drivers core;
  • Null block device driver;
  • Ublk userspace block driver;
  • Bluetooth drivers;
  • Counter interface drivers;
  • DMA engine subsystem;
  • DPLL subsystem;
  • GPU drivers;
  • HID subsystem;
  • Intel Trace Hub HW tracing drivers;
  • IIO ADC drivers;
  • IIO subsystem;
  • On-Chip Interconnect management framework;
  • IRQ chip drivers;
  • Modular ISDN driver;
  • LED subsystem;
  • Multiple devices driver;
  • UACCE accelerator framework;
  • MMC subsystem;
  • Ethernet bonding driver;
  • Network drivers;
  • Mellanox network drivers;
  • NVME drivers;
  • PHY drivers;
  • x86 platform drivers;
  • i.MX PM domains;
  • SCSI subsystem;
  • SLIMbus drivers;
  • SPI subsystem;
  • TCM subsystem;
  • W1 Dallas's 1-wire bus driver;
  • Xen hypervisor drivers;
  • BTRFS file system;
  • EFI Variable file system;
  • exFAT file system;
  • Ext4 file system;
  • HFS+ file system;
  • Network file system (NFS) client;
  • Network file system (NFS) server daemon;
  • NTFS3 file system;
  • SMB network file system;
  • Scheduler infrastructure;
  • Netfilter;
  • NFC subsystem;
  • Tracing infrastructure;
  • io_uring subsystem;
  • BPF subsystem;
  • Perf events;
  • Floating proportions library;
  • Memory management;
  • Bluetooth subsystem;
  • CAN network layer;
  • Ceph Core library;
  • Networking core;
  • IPv4 networking;
  • IPv6 networking;
  • L2TP protocol;
  • MAC80211 subsystem;
  • NET/ROM layer;
  • Packet sockets;
  • RDS protocol;
  • RxRPC session sockets;
  • Network traffic control;
  • SCTP protocol;
  • TLS protocol;
  • Unix domain sockets;
  • VMware vSockets driver;
  • Wireless networking;
  • ALSA AC97 driver;
  • Generic PCM loopback sound driver;
  • Creative Sound Blaster X-Fi driver;
  • AMD SoC Alsa drivers;
  • Texas InstrumentS Audio (ASoC/HDA) 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
24.04 LTS noble linux-image-6.8.0-1059-azure-fips –  6.8.0-1059.65+fips1  
linux-image-azure-fips –  6.8.0-1059.65+fips1  
linux-image-azure-fips-6.8 –  6.8.0-1059.65+fips1  

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References

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