Linux Distros Unpatched Vulnerability : CVE-2026-64582

critical Nessus Plugin ID 332749

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.

- RDMA/rxe: Fix a use-after-free problem in rxe_mmap rxe_mmap() removes a rxe_mmap_info struct from the pending_mmaps list and releases pending_lock while the struct's kref is still at 1:
list_del_init(&ip->pending_mmaps); spin_unlock_bh(&rxe->pending_lock); /* ref == 1, no lock held */ ret = remap_vmalloc_range(vma, ip->obj, 0); /* walks PTEs */ [...] rxe_vma_open(vma); /* kref_get, ref 2 */ remap_vmalloc_range_partial() walks PTEs without any lock. A concurrent DESTROY_CQ ioctl on another CPU calls: kref_put(&q->ip->ref, rxe_mmap_release) /* ref 10 */ vfree(ip->obj) /* clears vmalloc PTEs mid- walk */ kfree(ip) /* frees rxe_mmap_info */ This yields: 1. Kernel crash, vmalloc_to_page() returns NULL when vfree wins the per-PTE race -> vm_insert_page(NULL) GPF in validate_page_before_insert 2. Page UAF, vmalloc_to_page() reads a stale PTE before vfree clears it. User VMA holds a PTE to a free'd page which might eventually get reallocated later by vmalloc which allows the attacker to get a clean page-level UAF.
It is worth noting that even though a page-level UAF is possible given the strong primitive, it is statistically very difficult to achieve given the very short time window (after the last insert_page and before the kref_get). The call trace are as below: Oops: general protection fault, probably for non- canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 1000 PID: 413 Comm: poc Not tainted 7.0.0-rc5-dirty #28 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP:
0010:validate_page_before_insert+0x32/0x300 Code: e5 41 57 41 56 49 89 fe 41 55 41 54 53 48 89 f3 e8 93 b5 a3 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 7b 02 00 00 4c 8b 63 08 31 ff 4d 89 e5 41 83 e5 RSP: 0018:ffff88811b15f2f0 EFLAGS: 00000202 RAX: dffffc0000000000 RBX:
0000000000000000 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000008 RBP: ffff88811b15f318 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11:
0000000000000000 R12: ffff8881181eee00 R13: 0000000000000000 R14: ffff8881181eee00 R15: ffff8881181eee20 FS: 00007b1e000f76c0(0000) GS:ffff8884268e0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007b1e00a24ac0 CR3: 0000000116eb3000 CR4: 00000000000006f0 Call Trace: <TASK> insert_page+0x8f/0x190 ? __pfx_insert_page+0x10/0x10 ? kasan_save_alloc_info+0x38/0x60 vm_insert_page+0x2e7/0x400 remap_vmalloc_range_partial+0x212/0x3e0 remap_vmalloc_range+0x6e/0xb0 ?
__kasan_check_write+0x14/0x30 rxe_mmap+0x2e9/0x5d0 ib_uverbs_mmap+0x1ad/0x2c0 __mmap_region+0x12c2/0x2ad0 ? __pfx___mmap_region+0x10/0x10 ? __sanitizer_cov_trace_switch+0x58/0xb0 ? mas_prev_slot+0x360/0x39c0 ?
__sanitizer_cov_trace_switch+0x58/0xb0 ? mas_next_slot+0x1e5b/0x2f40 ?
__sanitizer_cov_trace_cmp8+0x18/0x30 ? unmapped_area_topdown+0x4dd/0x610 ? kfree+0x1b1/0x440 ? free_cpumask_var+0x16/0x30 ? __kasan_slab_free+0x7d/0xa0 ? __sanitizer_cov_trace_cmp8+0x18/0x30 mmap_region+0x2e6/0x3c0 do_mmap+0xa3e/0x12a0 ? __pfx_do_mmap+0x10/0x10 ? __kasan_check_write+0x14/0x30 ? down_write_killable+0xba/0x160 ? __pfx_down_write_killable+0x10/0x10 ?
__sanitizer_cov_trace_cmp4+0x16/0x30 vm_mmap_pgoff+0x2d4/0x4a0 ? __pfx_vm_mmap_pgoff+0x10/0x10 ? fget+0x1bf/0x270 ksys_mmap_pgoff+0x40c/0x690 ? __sanitizer_cov_trace_const_cmp4+0x16/0x30 ?
__pfx_ksys_mmap_pgoff+0x10/0x10 ? __kasan_check_write+0x14/0x30 ? _raw_spin_trylock+0xbb/0x130 ?
__pfx__raw_spin_trylock+0x10/0x10 __x64_sys_mmap+0x135/0x1e0 x64_sys_c ---truncated--- (CVE-2026-64582)

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://security-tracker.debian.org/tracker/CVE-2026-64582

Plugin Details

Severity: Critical

ID: 332749

File Name: unpatched_CVE_2026_64582.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 8/5/2026

Updated: 8/5/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.4

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

CVSS Score Source: CVE-2026-64582

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9

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

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

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:11.0, cpe:/o:debian:debian_linux:12.0, cpe:/o:debian:debian_linux:14.0, p-cpe:/a:debian:debian_linux:linux

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: 8/5/2026

Reference Information

CVE: CVE-2026-64582