Cyber Resilience

CVE-2026-43391

High

Published: 08 May 2026

Published
08 May 2026
Modified
26 May 2026
KEV Added
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Patch
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CVSS Score v3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0012 2.2th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-43391 is a high-severity an unspecified weakness vulnerability in Linux Linux Kernel. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 2.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

may_see_all_namespaces() helper that centralizes this policy until the nstree adapts.

CWE(s)
NVD-CWE-noinfo

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1611 Escape to Host Privilege Escalation
Adversaries may break out of a container or virtualized environment to gain access to the underlying host.
attack.mitre.org →
Why these techniques?

Kernel nsfs permission bypass enables local privilege escalation via namespace access and potential container/host escape by leaking privileged namespace info.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

Affected Assets

linux
linux kernel
7.0 · 6.18 — 6.19.9

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References