Linux Distros Unpatched Vulnerability : CVE-2026-43252

high Nessus Plugin ID 312897

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

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

- mptcp: pm: in-kernel: always set ID as avail when rm endp Syzkaller managed to find a combination of actions that was generating this warning: WARNING: net/mptcp/pm_kernel.c:1074 at
__mark_subflow_endp_available net/mptcp/pm_kernel.c:1074 [inline], CPU#1: syz.7.48/2535 WARNING:
net/mptcp/pm_kernel.c:1074 at mptcp_pm_nl_fullmesh net/mptcp/pm_kernel.c:1446 [inline], CPU#1:
syz.7.48/2535 WARNING: net/mptcp/pm_kernel.c:1074 at mptcp_pm_nl_set_flags_all net/mptcp/pm_kernel.c:1474 [inline], CPU#1: syz.7.48/2535 WARNING: net/mptcp/pm_kernel.c:1074 at mptcp_pm_nl_set_flags+0x5de/0x640 net/mptcp/pm_kernel.c:1538, CPU#1: syz.7.48/2535 Modules linked in: CPU: 1 UID: 0 PID: 2535 Comm: syz.7.48 Not tainted 6.18.0-03987-gea5f5e676cf5 #17 PREEMPT(voluntary) Hardware name: QEMU Ubuntu 25.10 PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_kernel.c:1074 [inline] RIP: 0010:mptcp_pm_nl_fullmesh net/mptcp/pm_kernel.c:1446 [inline] RIP: 0010:mptcp_pm_nl_set_flags_all net/mptcp/pm_kernel.c:1474 [inline] RIP:
0010:mptcp_pm_nl_set_flags+0x5de/0x640 net/mptcp/pm_kernel.c:1538 Code: 89 c7 e8 c5 8c 73 fe e9 f7 fd ff ff 49 83 ef 80 e8 b7 8c 73 fe 4c 89 ff be 03 00 00 00 e8 4a 29 e3 fe eb ac e8 a3 8c 73 fe 90 <0f> 0b 90 e9 3d ff ff ff e8 95 8c 73 fe b8 a1 ff ff ff eb 1a e8 89 RSP: 0018:ffffc9001535b820 EFLAGS: 00010287 netdevsim0: tun_chr_ioctl cmd 1074025677 RAX: ffffffff82da294d RBX: 0000000000000001 RCX: 0000000000080000 RDX: ffffc900096d0000 RSI: 00000000000006d6 RDI: 00000000000006d7 netdevsim0: linktype set to 823 RBP:
ffff88802cdb2240 R08: 00000000000104ae R09: ffffffffffffffff R10: ffffffff82da27d4 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88801246d8c0 R14: ffffc9001535b8b8 R15: ffff88802cdb1800 FS:
00007fc6ac5a76c0(0000) GS:ffff8880f90c8000(0000) knlGS:0000000000000000 netlink: 'syz.3.50': attribute type 5 has an invalid length. CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 netlink: 1232 bytes leftover after parsing attributes in process `syz.3.50'. CR2: 0000200000010000 CR3: 0000000025b1a000 CR4:
0000000000350ef0 Call Trace: <TASK> mptcp_pm_set_flags net/mptcp/pm_netlink.c:277 [inline] mptcp_pm_nl_set_flags_doit+0x1d7/0x210 net/mptcp/pm_netlink.c:282 genl_family_rcv_msg_doit+0x117/0x180 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x3a8/0x3f0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x16d/0x240 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x3e9/0x4c0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x4ab/0x5b0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg+0xc9/0xf0 net/socket.c:733 ____sys_sendmsg+0x272/0x3b0 net/socket.c:2608
___sys_sendmsg+0x2de/0x320 net/socket.c:2662 __sys_sendmsg net/socket.c:2694 [inline] __do_sys_sendmsg net/socket.c:2699 [inline] __se_sys_sendmsg net/socket.c:2697 [inline] __x64_sys_sendmsg+0x110/0x1a0 net/socket.c:2697 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xed/0x360 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc6adb66f6d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP:
002b:00007fc6ac5a6ff8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX:
00007fc6addf5fa0 RCX: 00007fc6adb66f6d RDX: 0000000000048084 RSI: 00002000000002c0 RDI: 000000000000000e RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11:
0000000000000246 R12: 000000000000 ---truncated--- (CVE-2026-43252)

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

Solution

There is no known solution at this time.

See Also

https://access.redhat.com/security/cve/cve-2026-43252

https://ubuntu.com/security/CVE-2026-43252

Plugin Details

Severity: High

ID: 312897

File Name: unpatched_CVE_2026_43252.nasl

Version: 1.2

Type: Local

Agent: unix

Family: Misc.

Published: 5/7/2026

Updated: 5/7/2026

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.0

CVSS v2

Risk Factor: Medium

Base Score: 4.9

Temporal Score: 4.2

Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2026-43252

CVSS v3

Risk Factor: High

Base Score: 7.1

Temporal Score: 6.5

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-core, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde-6.17, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-core, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-6.17, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency-hwe-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-ibm, p-cpe:/a:redhat:enterprise_linux:kernel-doc, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.3, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-devel, p-cpe:/a:canonical:ubuntu_linux:linux-azure-6.11, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-hwe, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.8, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.17, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-extra, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-6.2, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug, p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:kernel-64k-devel, cpe:/o:redhat:enterprise_linux:10, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-extra, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.0, p-cpe:/a:canonical:ubuntu_linux:linux-raspi, p-cpe:/a:redhat:enterprise_linux:kernel-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-extra, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-oracle, p-cpe:/a:canonical:ubuntu_linux:linux-aws-6.8, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.19, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-core, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-6.8, cpe:/o:canonical:ubuntu_linux:26.04, p-cpe:/a:canonical:ubuntu_linux:linux-realtime, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.13, p-cpe:/a:redhat:enterprise_linux:kernel-64k-core, p-cpe:/a:canonical:ubuntu_linux:linux-raspi2, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde-6.14, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs-devel, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-6.2, p-cpe:/a:redhat:enterprise_linux:kernel-core, p-cpe:/a:canonical:ubuntu_linux:linux-xilinx, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.14, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-6.11, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-nvidia-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-6.17, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-6.14, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.0, p-cpe:/a:redhat:enterprise_linux:kernel-abi-stablelists, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-tools, p-cpe:/a:canonical:ubuntu_linux:linux-aws, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.13, p-cpe:/a:redhat:enterprise_linux:perf, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-devel-matched, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency, p-cpe:/a:canonical:ubuntu_linux:linux-oem, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-5.8, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-core, p-cpe:/a:canonical:ubuntu_linux:linux-nvidia, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-6.14, p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel, p-cpe:/a:canonical:ubuntu_linux:linux-starfive-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde-6.8, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.14, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-devel, p-cpe:/a:redhat:enterprise_linux:kernel-uki-virt-addons, p-cpe:/a:canonical:ubuntu_linux:linux-nvidia-lowlatency, p-cpe:/a:canonical:ubuntu_linux:linux-gcp, p-cpe:/a:canonical:ubuntu_linux:linux-azure, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-extra, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-core, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-6.17, p-cpe:/a:canonical:ubuntu_linux:linux-aws-6.14, p-cpe:/a:redhat:enterprise_linux:kernel-64k-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules, p-cpe:/a:redhat:enterprise_linux:kernel-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-core, p-cpe:/a:canonical:ubuntu_linux:linux-gke-5.15, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency-hwe-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-ibm-6.8, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-starfive-6.5, cpe:/o:canonical:ubuntu_linux:25.10, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.6, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.8, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-gkeop-5.4, p-cpe:/a:redhat:enterprise_linux:kernel-64k, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency-hwe-6.11, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-core, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-6.14, p-cpe:/a:redhat:enterprise_linux:rv, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-uki-virt, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-6.8, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-core, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency-hwe-6.2, p-cpe:/a:redhat:enterprise_linux:libperf, p-cpe:/a:canonical:ubuntu_linux:linux-allwinner-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-6.14, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.17, p-cpe:/a:canonical:ubuntu_linux:linux-nvidia-6.11, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-6.17, p-cpe:/a:canonical:ubuntu_linux:linux-gkeop-5.15, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.13, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-core, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-6.8, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules, p-cpe:/a:canonical:ubuntu_linux:linux-raspi-realtime, p-cpe:/a:redhat:enterprise_linux:python3-perf, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-6.8, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-intel-iot-realtime, p-cpe:/a:canonical:ubuntu_linux:linux-gkeop, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-edge, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:rtla, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.13, p-cpe:/a:canonical:ubuntu_linux:linux, p-cpe:/a:redhat:enterprise_linux:kernel-devel-matched, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.11, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-core, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.11, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-core, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel, p-cpe:/a:canonical:ubuntu_linux:linux-gke-4.15, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-azure-nvidia, p-cpe:/a:redhat:enterprise_linux:kernel-rt, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.0, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules, p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra-matched, p-cpe:/a:redhat:enterprise_linux:kernel-debug-uki-virt, p-cpe:/a:canonical:ubuntu_linux:linux-azure-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-6.11, p-cpe:/a:canonical:ubuntu_linux:linux-aws-6.2, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump, p-cpe:/a:canonical:ubuntu_linux:linux-gke, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-intel-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-gke-5.4, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-extra, p-cpe:/a:canonical:ubuntu_linux:linux-azure-edge, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-nvidia-tegra, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k, p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules, p-cpe:/a:canonical:ubuntu_linux:linux-azure-6.14, p-cpe:/a:canonical:ubuntu_linux:linux-azure-6.5, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules, p-cpe:/a:redhat:enterprise_linux:kernel-modules-core, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-azure-nvidia-6.14, p-cpe:/a:canonical:ubuntu_linux:linux-aws-6.17, p-cpe:/a:redhat:enterprise_linux:kernel-debug, p-cpe:/a:canonical:ubuntu_linux:linux-aws-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde, p-cpe:/a:canonical:ubuntu_linux:linux-azure-6.8, p-cpe:/a:canonical:ubuntu_linux:linux-nvidia-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-nvidia-6.8, p-cpe:/a:canonical:ubuntu_linux:linux-starfive-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.8, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency-hwe-6.8, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.1, p-cpe:/a:canonical:ubuntu_linux:linux-riscv, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug, p-cpe:/a:canonical:ubuntu_linux:linux-azure-6.17, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.10

Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 5/6/2026

Reference Information

CVE: CVE-2026-43252