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Linux Distros Unpatched Vulnerability : CVE-2026-23327

high Nessus Plugin ID 303602

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.

 - cxl/mbox: validate payload size before accessing contents in cxl_payload_from_user_allowed() cxl_payload_from_user_allowed() casts and dereferences the input payload without first verifying its size.
 When a raw mailbox command is sent with an undersized payload (ie: 1 byte for CXL_MBOX_OP_CLEAR_LOG, which expects a 16-byte UUID), uuid_equal() reads past the allocated buffer, triggering a KASAN splat: BUG:
 KASAN: slab-out-of-bounds in memcmp+0x176/0x1d0 lib/string.c:683 Read of size 8 at addr ffff88810130f5c0 by task syz.1.62/2258 CPU: 2 UID: 0 PID: 2258 Comm: syz.1.62 Not tainted 6.19.0-dirty #3 PREEMPT(voluntary) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xab/0xe0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xce/0x650 mm/kasan/report.c:482 kasan_report+0xce/0x100 mm/kasan/report.c:595 memcmp+0x176/0x1d0 lib/string.c:683 uuid_equal include/linux/uuid.h:73 [inline] cxl_payload_from_user_allowed drivers/cxl/core/mbox.c:345 [inline] cxl_mbox_cmd_ctor drivers/cxl/core/mbox.c:368 [inline] cxl_validate_cmd_from_user drivers/cxl/core/mbox.c:522 [inline] cxl_send_cmd+0x9c0/0xb50 drivers/cxl/core/mbox.c:643 __cxl_memdev_ioctl drivers/cxl/core/memdev.c:698 [inline] cxl_memdev_ioctl+0x14f/0x190 drivers/cxl/core/memdev.c:713 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa8/0x330 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdaf331ba79 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP:
 002b:00007fdaf1d77038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX:
 00007fdaf3585fa0 RCX: 00007fdaf331ba79 RDX: 00002000000001c0 RSI: 00000000c030ce02 RDI: 0000000000000003 RBP: 00007fdaf33749df R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11:
 0000000000000246 R12: 0000000000000000 R13: 00007fdaf3586038 R14: 00007fdaf3585fa0 R15: 00007ffced2af768 </TASK> Add 'in_size' parameter to cxl_payload_from_user_allowed() and validate the payload is large enough. (CVE-2026-23327)

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-2026-23327

https://security-tracker.debian.org/tracker/CVE-2026-23327

Plugin Details

Severity: High

ID: 303602

File Name: unpatched_CVE_2026_23327.nasl

Version: 1.2

Type: local

Agent: unix

Family: Misc.

Published: 3/25/2026

Updated: 3/25/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

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-2026-23327

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: p-cpe:/a:debian:debian_linux:linux, p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:kernel-debug, p-cpe:/a:redhat:enterprise_linux:kernel-doc, p-cpe:/a:redhat:enterprise_linux:kernel-rt, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-modules, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-ipaclones-internal, p-cpe:/a:redhat:enterprise_linux:kernel-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-selftests-internal, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-64k-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-debug-uki-virt, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-rt-selftests-internal, p-cpe:/a:redhat:enterprise_linux:libperf, p-cpe:/a:redhat:enterprise_linux:rv, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-uki-virt-addons, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-extra, cpe:/o:redhat:enterprise_linux:10, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-internal, p-cpe:/a:redhat:enterprise_linux:libperf-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-headers, p-cpe:/a:redhat:enterprise_linux:perf, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug, p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel, p-cpe:/a:redhat:enterprise_linux:kernel-tools, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-rt-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules, p-cpe:/a:redhat:enterprise_linux:bpftool, p-cpe:/a:redhat:enterprise_linux:kernel-core, p-cpe:/a:redhat:enterprise_linux:kernel-cross-headers, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-core, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-devel, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-extra, p-cpe:/a:redhat:enterprise_linux:python3-perf, p-cpe:/a:redhat:enterprise_linux:kernel-abi-stablelists, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-internal, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-devel-matched, cpe:/o:debian:debian_linux:12.0, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k, p-cpe:/a:redhat:enterprise_linux:kernel-64k-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-64k-devel, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-uki-virt, p-cpe:/a:redhat:enterprise_linux:rtla, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-modules-partner, cpe:/o:debian:debian_linux:13.0, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debug-uki-virt-addons, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra-matched

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

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 3/25/2026

Reference Information

CVE: CVE-2026-23327