USN-8261-1

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)

Qualys discovered that several vulnerabilities existed in the AppArmor Linux kernel Security Module (LSM). An unprivileged local attacker could use these issues to load, replace, and remove arbitrary AppArmor profiles causing denial of service, exposure of sensitive information (kernel memory), local privilege escalation, or possibly escape a container. (LP: #2143853, CVE-2026-23268, CVE-2026-23269, CVE-2026-23403, CVE-2026-23404, CVE-2026-23405, CVE-2026-23406, CVE-2026-23407, CVE-2026-23408, CVE-2026-23409, CVE-2026-23410, CVE-2026-23411)

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;
• Nios II architecture;
• PA-RISC architecture;
• PowerPC architecture;
• RISC-V architecture;
• S390 architecture;
• Sun Sparc architecture;
• User-Mode Linux (UML);
• x86 architecture;
• Xtensa architecture;
• Block layer subsystem;
• Cryptographic API;
• Compute Acceleration Framework;
• ACPI drivers;
• ATM drivers;
• Drivers core;
• Block device driver;
• Network block device driver;
• Bluetooth drivers;
• Bus devices;
• Character device driver;
• Hardware random number generator core;
• TPM device driver;
• Clock framework and drivers;
• Data acquisition framework and drivers;
• CPU frequency scaling framework;
• Hardware crypto device drivers;
• Device frequency scaling framework;
• DMA engine subsystem;
• ARM SCMI message protocol;
• EFI core;
• Intel Stratix 10 firmware drivers;...