The vulnerability of the cifs_get_spnego_key() function in the cifs.upcall tool of the cifs-utils package in Linux kernel allows a attacker to elevate their privileges to root and execute arbitrary code.

🗓️ 01 Jun 2026 00:00:00Reported by FSTEC of Russia — Information Security Threat DatabaseType

bdu_fstec

bdu_fstec🔗 bdu.fstec.ru👁 7 Views

The vulnerability in cifs_get_spnego_key in cifs.upcall enables root privilege escalation and arbitrary code execution.

Reporter	Title	Published	Views	Family All 560
GithubExploit	Exploit for CVE-2026-46243	3 Jun 202600:15	–	githubexploit
GithubExploit	CIFSwitch	28 May 202605:38	–	githubexploit
GithubExploit	Exploit for CVE-2026-46243	2 Jun 202611:39	–	githubexploit
GithubExploit	Exploit for CVE-2026-46243	2 Jun 202611:39	–	githubexploit
ATTACKERKB	CVE-2026-46243	1 Jun 202616:22	–	attackerkb
Tenable Nessus	Amazon Linux 2023 : bpftool6.12, kernel6.12, kernel6.12-devel (ALAS2023-2026-1863)	22 Jun 202600:00	–	nessus
Tenable Nessus	Amazon Linux 2023 : bpftool6.18, kernel6.18, kernel6.18-devel (ALAS2023-2026-1864)	22 Jun 202600:00	–	nessus
Tenable Nessus	Amazon Linux 2023 : bpftool, kernel, kernel-devel (ALAS2023-2026-1865)	22 Jun 202600:00	–	nessus
Tenable Nessus	Amazon Linux 2 : kernel, --advisory ALAS2-2026-3374 (ALAS-2026-3374)	22 Jun 202600:00	–	nessus
Tenable Nessus	Amazon Linux 2 : kernel, --advisory ALAS2KERNEL-5.10-2026-122 (ALASKERNEL-5.10-2026-122)	22 Jun 202600:00	–	nessus

Vulners

Node

OR

canonical ubuntuMatch18.04

canonical ubuntuMatch20.04

oracle oracle_linuxMatch8

canonical ubuntuMatch22.04

amazon.com amazon_linuxMatch2023

oracle oracle_linuxMatch9

novell opensuse_leapMatch15.6

rocky_enterprise rocky_linuxMatch9

clement_lefebvre linux_mintMatch21.3

clement_lefebvre linux_mintMatch22.3

offensive_security kali_linuxMatch2021.4

offensive_security kali_linuxMatch2022.4

offensive_security kali_linuxMatch2023.4

offensive_security kali_linuxMatch2024.4

offensive_security kali_linuxMatch2025.4

offensive_security kali_linuxMatch2026.1

almalinux_os almalinuxMatch9.7

Source	Link
heyitsas	www.heyitsas.im/posts/cifswitch/
github	www.github.com/torvalds/linux/commit/3da1fdf4efbc490041eb4f836bf596201203f8f2
github	www.github.com/manizada/CIFSwitch/
git	www.git.kernel.org/stable/c/0aece6685fc80a8de492688ca2315fb86ec379c7
git	www.git.kernel.org/stable/c/2035acfb17221729b1b8ac335e941868a04ca079
git	www.git.kernel.org/stable/c/3da1fdf4efbc490041eb4f836bf596201203f8f2
git	www.git.kernel.org/stable/c/7713bd320ed4fc3d08a227cd8e41242219a16981
git	www.git.kernel.org/stable/c/91f89c1d83e80417629791fcef6af8140d7d01c8
git	www.git.kernel.org/stable/c/9544559e59438a4b609b2fdfa0763d8360572824
git	www.git.kernel.org/stable/c/a3bbda6502a9398b816fa2e71c9a3f955f58013d

05 Aug 2026 00:00Current

6Medium risk

Vulners AI Score6

CVSS 26.8

CVSS 38.8

EPSS0.00377

cifs upcall vulnerability spnego key flaw root privilege escalation arbitrary code execution unauthenticated access