In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate response sizes in ipc_validate_msg() ipc_validate_msg() computes the expected message size for each response type by adding (or multiplying) attacker-controlled fields from the daemon response to a fixed struct size in unsigned int arithmetic. Three cases can overflow: KSMBD_EVENT_RPC_REQUEST: msg_sz = sizeof(struct ksmbd_rpc_command) + resp->payload_sz; KSMBD_EVENT_SHARE_CONFIG_REQUEST: msg_sz = sizeof(struct ksmbd_share_config_response) + resp->payload_sz; KSMBD_EVENT_LOGIN_REQUEST_EXT: msg_sz = sizeof(struct ksmbd_login_response_ext) + resp->ngroups * sizeof(gid_t); resp->payload_sz is __u32 and resp->ngroups is __s32. Each addition can wrap in unsigned int; the multiplication by sizeof(gid_t) mixes signed and size_t, so a negative ngroups is converted to SIZE_MAX before the multiply. A wrapped value of msg_sz that happens to equal entry->msg_sz bypasses the size check on the next line, and downstream consumers (smb2pdu.c:6742 memcpy using rpc_resp->payload_sz, kmemdup in ksmbd_alloc_user using resp_ext->ngroups) then trust the unverified length. Use check_add_overflow() on the RPC_REQUEST and SHARE_CONFIG_REQUEST paths to detect integer overflow without constraining functional payload size; userspace ksmbd-tools grows NDR responses in 4096-byte chunks for calls like NetShareEnumAll, so a hard transport cap is unworkable on the response side. For LOGIN_REQUEST_EXT, reject resp->ngroups outside the signed [0, NGROUPS_MAX] range up front and report the error from ipc_validate_msg() so it fires at the IPC boundary; with that bound the subsequent multiplication and addition stay well below UINT_MAX. The now-redundant ngroups check and pr_err in ksmbd_alloc_user() are removed. This is the response-side analogue of aab98e2dbd64 ("ksmbd: fix integer overflows on 32 bit systems"), which hardened the request side.

The remote Ubuntu 26.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8507-1 advisory.

    It was discovered that some AMD processors did not properly clear data in the floating point divider unit     during speculative execution. A local attacker could use this to expose sensitive information.
    (CVE-2025-54505)

    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;

    - Block layer subsystem;

    - Cryptographic API;

    - Rados block device (RBD) driver;

    - Compressed RAM block device driver;

    - Character device driver;

    - TPM device driver;

    - Hardware crypto device drivers;

    - EDAC drivers;

    - GPU drivers;

    - Greybus drivers;

    - HID subsystem;

    - Microsoft Hyper-V drivers;

    - Hardware monitoring drivers;

    - I2C subsystem;

    - IIO subsystem;

    - InfiniBand drivers;

    - Input Device core drivers;

    - LED subsystem;

    - Multiple devices driver;

    - Media drivers;

    - IBM Advanced System Management driver;

    - MTD block device drivers;

    - Network drivers;

    - Microsoft Azure Network Adapter (MANA) driver;

    - NTB driver;

    - NVME drivers;

    - Device tree and open firmware driver;

    - PCI subsystem;

    - Remote Processor subsystem;

    - SCSI subsystem;

    - SPI subsystem;

    - Realtek RTL8723BS SDIO drivers;

    - SM750 framebuffer staging driver;

    - Thermal drivers;

    - USB Gadget drivers;

    - USB over IP driver;

    - VFIO drivers;

    - Framebuffer layer;

    - 9P distributed file system;

    - AFS file system;

    - Ceph distributed file system;

    - File systems infrastructure;

    - EROFS file system;

    - Ext4 file system;

    - F2FS file system;

    - FUSE (File system in Userspace);

    - Journaling layer for block devices (JBD2);

    - NILFS2 file system;

    - File system notification infrastructure;

    - NTFS3 file system;

    - OCFS2 file system;

    - SMB network file system;

    - UDF file system;

    - XFS file system;

    - Codetag library;

    - Memory management;

    - Memory Management;

    - KVM subsystem;

    - Tracing infrastructure;

    - User-space API (UAPI);

    - io_uring subsystem;

    - Locking primitives;

    - Timer subsystem;

    - Scatterlist API;

    - Heterogeneous memory management;

    - KASAN memory debugging framework;

    - Bluetooth subsystem;

    - Ethernet bridge;

    - CAIF protocol;

    - CAN network layer;

    - Ceph Core library;

    - IPv4 networking;

    - IPv6 networking;

    - Multipath TCP;

    - Netfilter;

    - NFC subsystem;

    - Packet sockets;

    - Qualcomm IPC Router (QRTR);

    - RDS protocol;

    - RxRPC session sockets;

    - SMC sockets;

    - Stream parser;

    - Landlock security;

    - SELinux security module;

    - ALSA framework;

    - Generic PCM loopback sound driver;

    - FireWire sound drivers;

    - Creative Sound Blaster X-Fi driver;

    - QCOM ASoC drivers;

    - USB sound devices;

    - Objtool; (CVE-2026-31532, CVE-2026-31574, CVE-2026-31575, CVE-2026-31576, CVE-2026-31577,     CVE-2026-31578, CVE-2026-31579, CVE-2026-31580, CVE-2026-31581, CVE-2026-31582, CVE-2026-31583,     CVE-2026-31584, CVE-2026-31585, CVE-2026-31586, CVE-2026-31587, CVE-2026-31588, CVE-2026-31589,     CVE-2026-31590, CVE-2026-31591, CVE-2026-31592, CVE-2026-31593, CVE-2026-31594, CVE-2026-31595,     CVE-2026-31596, CVE-2026-31597, CVE-2026-31598, CVE-2026-31599, CVE-2026-31600, CVE-2026-31601,     CVE-2026-31602, CVE-2026-31603, CVE-2026-31604, CVE-2026-31605, CVE-2026-31606, CVE-2026-31607,     CVE-2026-31608, CVE-2026-31609, CVE-2026-31610, CVE-2026-31611, CVE-2026-31612, CVE-2026-31613,     CVE-2026-31614, CVE-2026-31615, CVE-2026-31616, CVE-2026-31617, CVE-2026-31618, CVE-2026-31619,     CVE-2026-31620, CVE-2026-31621, CVE-2026-31622, CVE-2026-31623, CVE-2026-31624, CVE-2026-31625,     CVE-2026-31626, CVE-2026-31627, CVE-2026-31628, CVE-2026-31629, CVE-2026-31686, CVE-2026-31694,     CVE-2026-31696, CVE-2026-31697, CVE-2026-31698, CVE-2026-31699, CVE-2026-31700, CVE-2026-31701,     CVE-2026-31702, CVE-2026-31703, CVE-2026-31704, CVE-2026-31705, CVE-2026-31706, CVE-2026-31707,     CVE-2026-31708, CVE-2026-31709, CVE-2026-31710, CVE-2026-31711, CVE-2026-31712, CVE-2026-31713,     CVE-2026-31714, CVE-2026-31715, CVE-2026-31716, CVE-2026-31717, CVE-2026-31718, CVE-2026-31719,     CVE-2026-43058, CVE-2026-43071, CVE-2026-43072, CVE-2026-43073, CVE-2026-43348, CVE-2026-43349,     CVE-2026-43350, CVE-2026-43491, CVE-2026-43493, CVE-2026-43499, CVE-2026-43501, CVE-2026-45986,     CVE-2026-45987, CVE-2026-45988, CVE-2026-45989, CVE-2026-45990, CVE-2026-45991, CVE-2026-45994,     CVE-2026-45995, CVE-2026-45996, CVE-2026-45997, CVE-2026-45999, CVE-2026-46001, CVE-2026-46002,     CVE-2026-46003, CVE-2026-46004, CVE-2026-46005, CVE-2026-46006, CVE-2026-46007, CVE-2026-46008,     CVE-2026-46009, CVE-2026-46010, CVE-2026-46011, CVE-2026-46012, CVE-2026-46013, CVE-2026-46014,     CVE-2026-46015, CVE-2026-46016, CVE-2026-46018, CVE-2026-46019, CVE-2026-46020, CVE-2026-46021,     CVE-2026-46022, CVE-2026-46023, CVE-2026-46024, CVE-2026-46025, CVE-2026-46026, CVE-2026-46027,     CVE-2026-46028, CVE-2026-46029, CVE-2026-46030, CVE-2026-46031, CVE-2026-46032, CVE-2026-46033,     CVE-2026-46034, CVE-2026-46035, CVE-2026-46036, CVE-2026-46037, CVE-2026-46038, CVE-2026-46039,     CVE-2026-46040, CVE-2026-46041, CVE-2026-46042, CVE-2026-46043, CVE-2026-46044, CVE-2026-46045,     CVE-2026-46046, CVE-2026-46047, CVE-2026-46049, CVE-2026-46050, CVE-2026-46051, CVE-2026-46052,     CVE-2026-46053, CVE-2026-46054, CVE-2026-46056, CVE-2026-46057, CVE-2026-46058, CVE-2026-46059,     CVE-2026-46060, CVE-2026-46061, CVE-2026-46062, CVE-2026-46063, CVE-2026-46064, CVE-2026-46065,     CVE-2026-46066, CVE-2026-46067, CVE-2026-46068, CVE-2026-46069, CVE-2026-46070, CVE-2026-46071,     CVE-2026-46072, CVE-2026-46073, CVE-2026-46074, CVE-2026-46075, CVE-2026-46076, CVE-2026-46077,     CVE-2026-46078, CVE-2026-46079, CVE-2026-46080, CVE-2026-46081, CVE-2026-46082, CVE-2026-46083,     CVE-2026-46084, CVE-2026-46085, CVE-2026-46086, CVE-2026-46087, CVE-2026-46088, CVE-2026-46089,     CVE-2026-46090, CVE-2026-46091, CVE-2026-46092, CVE-2026-46093, CVE-2026-46094, CVE-2026-46095,     CVE-2026-46096, CVE-2026-46097, CVE-2026-46098, CVE-2026-46099, CVE-2026-46100, CVE-2026-46101,     CVE-2026-46102, CVE-2026-46103, CVE-2026-46115, CVE-2026-46119, CVE-2026-46135, CVE-2026-46137,     CVE-2026-46155, CVE-2026-46185, CVE-2026-46195, CVE-2026-46243, CVE-2026-46244, CVE-2026-46276,     CVE-2026-46277, CVE-2026-46278, CVE-2026-46279, CVE-2026-46280, CVE-2026-46281, CVE-2026-46282,     CVE-2026-46283, CVE-2026-46284, CVE-2026-46285, CVE-2026-46286, CVE-2026-46287, CVE-2026-46288,     CVE-2026-46289, CVE-2026-46316, CVE-2026-46332, CVE-2026-52904, CVE-2026-52905, CVE-2026-52906,     CVE-2026-52907, CVE-2026-52933)

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 26.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8488-1 advisory.

    It was discovered that some AMD processors did not properly clear data in the floating point divider unit     during speculative execution. A local attacker could use this to expose sensitive information.
    (CVE-2025-54505)

    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;

    - Block layer subsystem;

    - Cryptographic API;

    - Rados block device (RBD) driver;

    - Compressed RAM block device driver;

    - Character device driver;

    - TPM device driver;

    - Hardware crypto device drivers;

    - EDAC drivers;

    - GPU drivers;

    - Greybus drivers;

    - HID subsystem;

    - Microsoft Hyper-V drivers;

    - Hardware monitoring drivers;

    - I2C subsystem;

    - IIO subsystem;

    - InfiniBand drivers;

    - Input Device core drivers;

    - LED subsystem;

    - Multiple devices driver;

    - Media drivers;

    - IBM Advanced System Management driver;

    - MTD block device drivers;

    - Network drivers;

    - Microsoft Azure Network Adapter (MANA) driver;

    - NTB driver;

    - NVME drivers;

    - Device tree and open firmware driver;

    - PCI subsystem;

    - Remote Processor subsystem;

    - SCSI subsystem;

    - SPI subsystem;

    - Realtek RTL8723BS SDIO drivers;

    - SM750 framebuffer staging driver;

    - Thermal drivers;

    - USB Gadget drivers;

    - USB over IP driver;

    - VFIO drivers;

    - Framebuffer layer;

    - 9P distributed file system;

    - AFS file system;

    - Ceph distributed file system;

    - File systems infrastructure;

    - EROFS file system;

    - Ext4 file system;

    - F2FS file system;

    - FUSE (File system in Userspace);

    - Journaling layer for block devices (JBD2);

    - NILFS2 file system;

    - File system notification infrastructure;

    - NTFS3 file system;

    - OCFS2 file system;

    - SMB network file system;

    - UDF file system;

    - XFS file system;

    - Codetag library;

    - Memory management;

    - Memory Management;

    - KVM subsystem;

    - Tracing infrastructure;

    - User-space API (UAPI);

    - io_uring subsystem;

    - Locking primitives;

    - Timer subsystem;

    - Scatterlist API;

    - Heterogeneous memory management;

    - KASAN memory debugging framework;

    - Bluetooth subsystem;

    - Ethernet bridge;

    - CAIF protocol;

    - CAN network layer;

    - Ceph Core library;

    - IPv4 networking;

    - IPv6 networking;

    - Multipath TCP;

    - Netfilter;

    - NFC subsystem;

    - Packet sockets;

    - Qualcomm IPC Router (QRTR);

    - RDS protocol;

    - RxRPC session sockets;

    - SMC sockets;

    - Stream parser;

    - Landlock security;

    - SELinux security module;

    - ALSA framework;

    - Generic PCM loopback sound driver;

    - FireWire sound drivers;

    - Creative Sound Blaster X-Fi driver;

    - QCOM ASoC drivers;

    - USB sound devices;

    - Objtool; (CVE-2026-31532, CVE-2026-31574, CVE-2026-31575, CVE-2026-31576, CVE-2026-31577,     CVE-2026-31578, CVE-2026-31579, CVE-2026-31580, CVE-2026-31581, CVE-2026-31582, CVE-2026-31583,     CVE-2026-31584, CVE-2026-31585, CVE-2026-31586, CVE-2026-31587, CVE-2026-31588, CVE-2026-31589,     CVE-2026-31590, CVE-2026-31591, CVE-2026-31592, CVE-2026-31593, CVE-2026-31594, CVE-2026-31595,     CVE-2026-31596, CVE-2026-31597, CVE-2026-31598, CVE-2026-31599, CVE-2026-31600, CVE-2026-31601,     CVE-2026-31602, CVE-2026-31603, CVE-2026-31604, CVE-2026-31605, CVE-2026-31606, CVE-2026-31607,     CVE-2026-31608, CVE-2026-31609, CVE-2026-31610, CVE-2026-31611, CVE-2026-31612, CVE-2026-31613,     CVE-2026-31614, CVE-2026-31615, CVE-2026-31616, CVE-2026-31617, CVE-2026-31618, CVE-2026-31619,     CVE-2026-31620, CVE-2026-31621, CVE-2026-31622, CVE-2026-31623, CVE-2026-31624, CVE-2026-31625,     CVE-2026-31626, CVE-2026-31627, CVE-2026-31628, CVE-2026-31629, CVE-2026-31686, CVE-2026-31694,     CVE-2026-31696, CVE-2026-31697, CVE-2026-31698, CVE-2026-31699, CVE-2026-31700, CVE-2026-31701,     CVE-2026-31702, CVE-2026-31703, CVE-2026-31704, CVE-2026-31705, CVE-2026-31706, CVE-2026-31707,     CVE-2026-31708, CVE-2026-31709, CVE-2026-31710, CVE-2026-31711, CVE-2026-31712, CVE-2026-31713,     CVE-2026-31714, CVE-2026-31715, CVE-2026-31716, CVE-2026-31717, CVE-2026-31718, CVE-2026-31719,     CVE-2026-43058, CVE-2026-43071, CVE-2026-43072, CVE-2026-43073, CVE-2026-43348, CVE-2026-43349,     CVE-2026-43350, CVE-2026-43491, CVE-2026-43493, CVE-2026-43499, CVE-2026-43501, CVE-2026-45986,     CVE-2026-45987, CVE-2026-45988, CVE-2026-45989, CVE-2026-45990, CVE-2026-45991, CVE-2026-45994,     CVE-2026-45995, CVE-2026-45996, CVE-2026-45997, CVE-2026-45999, CVE-2026-46001, CVE-2026-46002,     CVE-2026-46003, CVE-2026-46004, CVE-2026-46005, CVE-2026-46006, CVE-2026-46007, CVE-2026-46008,     CVE-2026-46009, CVE-2026-46010, CVE-2026-46011, CVE-2026-46012, CVE-2026-46013, CVE-2026-46014,     CVE-2026-46015, CVE-2026-46016, CVE-2026-46018, CVE-2026-46019, CVE-2026-46020, CVE-2026-46021,     CVE-2026-46022, CVE-2026-46023, CVE-2026-46024, CVE-2026-46025, CVE-2026-46026, CVE-2026-46027,     CVE-2026-46028, CVE-2026-46029, CVE-2026-46030, CVE-2026-46031, CVE-2026-46032, CVE-2026-46033,     CVE-2026-46034, CVE-2026-46035, CVE-2026-46036, CVE-2026-46037, CVE-2026-46038, CVE-2026-46039,     CVE-2026-46040, CVE-2026-46041, CVE-2026-46042, CVE-2026-46043, CVE-2026-46044, CVE-2026-46045,     CVE-2026-46046, CVE-2026-46047, CVE-2026-46049, CVE-2026-46050, CVE-2026-46051, CVE-2026-46052,     CVE-2026-46053, CVE-2026-46054, CVE-2026-46056, CVE-2026-46057, CVE-2026-46058, CVE-2026-46059,     CVE-2026-46060, CVE-2026-46061, CVE-2026-46062, CVE-2026-46063, CVE-2026-46064, CVE-2026-46065,     CVE-2026-46066, CVE-2026-46067, CVE-2026-46068, CVE-2026-46069, CVE-2026-46070, CVE-2026-46071,     CVE-2026-46072, CVE-2026-46073, CVE-2026-46074, CVE-2026-46075, CVE-2026-46076, CVE-2026-46077,     CVE-2026-46078, CVE-2026-46079, CVE-2026-46080, CVE-2026-46081, CVE-2026-46082, CVE-2026-46083,     CVE-2026-46084, CVE-2026-46085, CVE-2026-46086, CVE-2026-46087, CVE-2026-46088, CVE-2026-46089,     CVE-2026-46090, CVE-2026-46091, CVE-2026-46092, CVE-2026-46093, CVE-2026-46094, CVE-2026-46095,     CVE-2026-46096, CVE-2026-46097, CVE-2026-46098, CVE-2026-46099, CVE-2026-46100, CVE-2026-46101,     CVE-2026-46102, CVE-2026-46103, CVE-2026-46115, CVE-2026-46119, CVE-2026-46135, CVE-2026-46137,     CVE-2026-46155, CVE-2026-46185, CVE-2026-46195, CVE-2026-46243, CVE-2026-46244, CVE-2026-46276,     CVE-2026-46277, CVE-2026-46278, CVE-2026-46279, CVE-2026-46280, CVE-2026-46281, CVE-2026-46282,     CVE-2026-46283, CVE-2026-46284, CVE-2026-46285, CVE-2026-46286, CVE-2026-46287, CVE-2026-46288,     CVE-2026-46289, CVE-2026-46316, CVE-2026-46332, CVE-2026-52904, CVE-2026-52905, CVE-2026-52906,     CVE-2026-52907, CVE-2026-52933)

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.

An update of the linux package has been released.

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

  - ksmbd: validate response sizes in ipc_validate_msg() ipc_validate_msg() computes the expected message size     for each response type by adding (or multiplying) attacker-controlled fields from the daemon response to a     fixed struct size in unsigned int arithmetic. Three cases can overflow: KSMBD_EVENT_RPC_REQUEST: msg_sz =     sizeof(struct ksmbd_rpc_command) + resp->payload_sz; KSMBD_EVENT_SHARE_CONFIG_REQUEST: msg_sz =     sizeof(struct ksmbd_share_config_response) + resp->payload_sz; KSMBD_EVENT_LOGIN_REQUEST_EXT: msg_sz =     sizeof(struct ksmbd_login_response_ext) + resp->ngroups * sizeof(gid_t); resp->payload_sz is __u32 and     resp->ngroups is __s32. Each addition can wrap in unsigned int; the multiplication by sizeof(gid_t) mixes     signed and size_t, so a negative ngroups is converted to SIZE_MAX before the multiply. A wrapped value of     msg_sz that happens to equal entry->msg_sz bypasses the size check on the next line, and downstream     consumers (smb2pdu.c:6742 memcpy using rpc_resp->payload_sz, kmemdup in ksmbd_alloc_user using     resp_ext->ngroups) then trust the unverified length. Use check_add_overflow() on the RPC_REQUEST and     SHARE_CONFIG_REQUEST paths to detect integer overflow without constraining functional payload size;
    userspace ksmbd-tools grows NDR responses in 4096-byte chunks for calls like NetShareEnumAll, so a hard     transport cap is unworkable on the response side. For LOGIN_REQUEST_EXT, reject resp->ngroups outside the     signed [0, NGROUPS_MAX] range up front and report the error from ipc_validate_msg() so it fires at the IPC     boundary; with that bound the subsequent multiplication and addition stay well below UINT_MAX. The now-     redundant ngroups check and pr_err in ksmbd_alloc_user() are removed. This is the response-side analogue     of aab98e2dbd64 (ksmbd: fix integer overflows on 32 bit systems), which hardened the request side.
    (CVE-2026-31707)

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

ID	Name	Product	Family	Severity
325421	Ubuntu 26.04 LTS : Linux kernel (NVIDIA) vulnerabilities (USN-8507-1)	Nessus	Ubuntu Local Security Checks	low
325017	Ubuntu 26.04 LTS : Linux kernel vulnerabilities (USN-8488-1)	Nessus	Ubuntu Local Security Checks	low
318365	Photon OS 5.0: Linux PHSA-2026-5.0-0849	Nessus	PhotonOS Local Security Checks	high
311633	Linux Distros Unpatched Vulnerability : CVE-2026-31707	Nessus	Misc.	high

Detections

Analytics

CVE-2026-31707

high

Tenable Plugins

low

low

high

high