USN-8374-1: Linux kernel vulnerabilities

It was discovered that the Linux kernel algifaead 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, 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 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: - S390 architecture; - Cryptographic API; - GPU drivers; - Ethernet bonding driver; - Network file system (NFS) server daemon; - Distributed Switch Architecture; - Netfilter; - Control group (cgroup); - Kernel kexec() syscall; - Memory management; - MAC80211 subsystem; - Multipath TCP; - Packet sockets; - RDS protocol; - RxRPC session sockets; - TLS protocol; - Unix domain sockets; - AppArmor security module; (CVE-2025-71088, CVE-2025-71090, CVE-2025-71127, CVE-2025-71134, CVE-2025-71139, CVE-2025-71141, CVE-2025-71142, CVE-2025-71144, CVE-2025-71152, CVE-2025-71155, CVE-2026-23274, CVE-2026-23351, CVE-2026-23394, CVE-2026-31419, CVE-2026-31504, CVE-2026-31533, CVE-2026-31676, CVE-2026-43033, CVE-2026-43077, CVE-2026-43078, CVE-2026-43494, CVE-2026-45966, CVE-2026-46028)