In the Linux kernel, the following vulnerability has been resolved: apparmor: fix NULL pointer dereference in __unix_needs_revalidation When receiving file descriptors via SCM_RIGHTS, both the socket pointer and the socket's sk pointer can be NULL during socket setup or teardown, causing NULL pointer dereferences in __unix_needs_revalidation(). This is a regression in AppArmor 5.0.0 (kernel 6.17+) where the new __unix_needs_revalidation() function was added without proper NULL checks. The crash manifests as: BUG: kernel NULL pointer dereference, address: 0x0000000000000018 RIP: aa_file_perm+0xb7/0x3b0 (or +0xbe/0x3b0, +0xc0/0x3e0) Call Trace: apparmor_file_receive+0x42/0x80 security_file_receive+0x2e/0x50 receive_fd+0x1d/0xf0 scm_detach_fds+0xad/0x1c0 The function dereferences sock->sk->sk_family without checking if either sock or sock->sk is NULL first. Add NULL checks for both sock and sock->sk before accessing sk_family.

The remote Ubuntu 24.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8508-1 advisory.

    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;

    - S390 architecture;

    - Block layer subsystem;

    - Cryptographic API;

    - DMA engine subsystem;

    - GPU drivers;

    - InfiniBand drivers;

    - Ethernet bonding driver;

    - STMicroelectronics network drivers;

    - Network drivers;

    - NVME drivers;

    - SCSI subsystem;

    - USB over IP driver;

    - File systems infrastructure;

    - Ext4 file system;

    - Network file system (NFS) server daemon;

    - SMB network file system;

    - Kernel thread helper (kthread);

    - Distributed Switch Architecture;

    - IPv6 networking;

    - Netfilter;

    - Tracing infrastructure;

    - Control group (cgroup);

    - Kernel exit() syscall;

    - Scatterlist API;

    - Memory management;

    - B.A.T.M.A.N. meshing protocol;

    - Ethernet bridge;

    - Ceph Core library;

    - IPv4 networking;

    - MAC80211 subsystem;

    - Multipath TCP;

    - Packet sockets;

    - RxRPC session sockets;

    - SMC sockets;

    - TLS protocol;

    - Unix domain sockets;

    - X.25 network layer;

    - AppArmor security module; (CVE-2025-71088, CVE-2025-71090, CVE-2025-71127, CVE-2025-71134,     CVE-2025-71141, CVE-2025-71142, CVE-2025-71144, CVE-2025-71152, CVE-2025-71155, CVE-2026-22984,     CVE-2026-23112, CVE-2026-23231, CVE-2026-23272, CVE-2026-23273, CVE-2026-23274, CVE-2026-23278,     CVE-2026-23351, CVE-2026-23392, CVE-2026-23394, CVE-2026-23427, CVE-2026-23428, CVE-2026-23450,     CVE-2026-23455, CVE-2026-31402, CVE-2026-31418, CVE-2026-31419, CVE-2026-31436, CVE-2026-31448,     CVE-2026-31478, CVE-2026-31504, CVE-2026-31533, CVE-2026-31607, CVE-2026-31635, CVE-2026-31637,     CVE-2026-31649, CVE-2026-31657, CVE-2026-31659, CVE-2026-31668, CVE-2026-31669, CVE-2026-31682,     CVE-2026-31685, CVE-2026-31718, CVE-2026-43011, CVE-2026-43033, CVE-2026-43037, CVE-2026-43038,     CVE-2026-43071, CVE-2026-43077, CVE-2026-43078, CVE-2026-43083, CVE-2026-43114, CVE-2026-43117,     CVE-2026-43125, CVE-2026-43186, CVE-2026-43197, CVE-2026-43304, CVE-2026-43341, CVE-2026-43376,     CVE-2026-43378, CVE-2026-43383, CVE-2026-43384, CVE-2026-43402, CVE-2026-43406, CVE-2026-43407,     CVE-2026-43414, CVE-2026-43493, CVE-2026-43501, CVE-2026-45898, CVE-2026-45966, CVE-2026-45988,     CVE-2026-46028, CVE-2026-46039, CVE-2026-46043, CVE-2026-46115, CVE-2026-46119, CVE-2026-46135,     CVE-2026-46185, CVE-2026-46195, CVE-2026-46243, CVE-2026-46244, CVE-2026-46266, CVE-2026-46289,     CVE-2026-46316, CVE-2026-46325)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 24.04 LTS / 25.10 host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8374-1 advisory.

    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, 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)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - In the Linux kernel, the following vulnerability has been resolved: apparmor: fix NULL pointer dereference     in __unix_needs_revalidation When receiving file descriptors via SCM_RIGHTS, both the socket pointer and     the socket's sk pointer can be NULL during socket setup or teardown, causing NULL pointer dereferences in
    __unix_needs_revalidation(). This is a regression in AppArmor 5.0.0 (kernel 6.17+) where the new
    __unix_needs_revalidation() function was added without proper NULL checks. The crash manifests as: BUG:
    kernel NULL pointer dereference, address: 0x0000000000000018 RIP: aa_file_perm+0xb7/0x3b0 (or +0xbe/0x3b0,     +0xc0/0x3e0) Call Trace: apparmor_file_receive+0x42/0x80 security_file_receive+0x2e/0x50     receive_fd+0x1d/0xf0 scm_detach_fds+0xad/0x1c0 The function dereferences sock->sk->sk_family without     checking if either sock or sock->sk is NULL first. Add NULL checks for both sock and sock->sk before     accessing sk_family. (CVE-2026-45966)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
325425	Ubuntu 24.04 LTS : Linux kernel (NVIDIA) vulnerabilities (USN-8508-1)	Nessus	Ubuntu Local Security Checks	critical
318635	Ubuntu 24.04 LTS / 25.10 : Linux kernel vulnerabilities (USN-8374-1)	Nessus	Ubuntu Local Security Checks	high
318434	Linux Distros Unpatched Vulnerability : CVE-2026-45966	Nessus	Misc.	medium

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CVE-2026-45966

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