High severity · published May 8, 2026
CVE-2026-43391
nsfs: tighten permission checks for handle opening
8.8
CVSS
0.1%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
nsfs: tighten permission checks for handle opening
Even privileged services should not necessarily be able to see other
privileged service's namespaces so they can't leak information to each
other. Use may_see_all_namespaces() helper that centralizes this policy
until the nstree adapts.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 2% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
6.18 before 6.19.9; 7.0; 7.0 · source: NVD
LI
Linux · Linux
5222470b2fbb3740f931f189db33dd1367b1ae75 before 24ebaf6676ae4f74f4856eb645959b15e62bc1b4; 5222470b2fbb3740f931f189db33dd1367b1ae75 before 1797ee11451f1b2be69863a9f5bd43b948813fdf; 5222470b2fbb3740f931f189db33dd1367b1ae75 before d2324a9317f00013facb0ba00b00440e19d2af5e; 6.18 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-43391
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-43391
Patch
https://git.kernel.org/stable/c/1797ee11451f1b2be69863a9f5bd43b948813fdf
git.kernel.org
https://git.kernel.org/stable/c/24ebaf6676ae4f74f4856eb645959b15e62bc1b4
Patch
https://git.kernel.org/stable/c/d2324a9317f00013facb0ba00b00440e19d2af5e
More from Kernel
9.8
CVE-2025-39682
tls: fix handling of zero-length records on the rx_list
8.8
CVE-2026-53266
netfilter: bridge: make ebt_snat ARP rewrite writable
8.8
CVE-2013-6282
Linux Kernel Improper Input Validation Vulnerability
8.4
CVE-2022-0185
Linux Kernel Heap-Based Buffer Overflow Vulnerability
8.4
CVE-2013-2094
Linux Kernel Privilege Escalation Vulnerability