In the Linux kernel, the following vulnerability has been resolved: nsfs: tighten permission checks for handle opening Even privileged services… (CVE-2026-43391)
A high severity vulnerability in the Linux kernel related to namespace filesystem (nsfs) permission checks has been resolved. The issue involved insufficient permission checks when opening handles, potentially allowing privileged services to access other privileged services' namespaces and leak information. The fix centralizes permission policy using the may_see_all_namespaces() helper function to prevent unauthorized namespace visibility.
AI Analysis
Technical Summary
CVE-2026-43391 addresses a Linux kernel vulnerability in the nsfs subsystem where permission checks for handle opening were insufficient. This flaw could allow privileged services to view namespaces of other privileged services, leading to potential information leakage. The remediation involved tightening these permission checks by employing the may_see_all_namespaces() helper, which centralizes the policy until the namespace tree (nstree) subsystem is adapted accordingly.
Potential Impact
The vulnerability could allow privileged services to bypass intended namespace isolation, potentially leaking sensitive information between namespaces. The CVSS score of 8.8 indicates high impact on confidentiality, integrity, and availability. However, there are no known exploits in the wild at this time.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to tighten permission checks using the may_see_all_namespaces() helper. Users and administrators should apply the official kernel updates that include this fix. Since no patch links are provided here, consult the official Linux kernel advisories or distributions for the updated kernel versions containing this remediation.
In the Linux kernel, the following vulnerability has been resolved: nsfs: tighten permission checks for handle opening Even privileged services… (CVE-2026-43391)
Description
A high severity vulnerability in the Linux kernel related to namespace filesystem (nsfs) permission checks has been resolved. The issue involved insufficient permission checks when opening handles, potentially allowing privileged services to access other privileged services' namespaces and leak information. The fix centralizes permission policy using the may_see_all_namespaces() helper function to prevent unauthorized namespace visibility.
CVSS v3.1
Score 8.8high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-43391 addresses a Linux kernel vulnerability in the nsfs subsystem where permission checks for handle opening were insufficient. This flaw could allow privileged services to view namespaces of other privileged services, leading to potential information leakage. The remediation involved tightening these permission checks by employing the may_see_all_namespaces() helper, which centralizes the policy until the namespace tree (nstree) subsystem is adapted accordingly.
Potential Impact
The vulnerability could allow privileged services to bypass intended namespace isolation, potentially leaking sensitive information between namespaces. The CVSS score of 8.8 indicates high impact on confidentiality, integrity, and availability. However, there are no known exploits in the wild at this time.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to tighten permission checks using the may_see_all_namespaces() helper. Users and administrators should apply the official kernel updates that include this fix. Since no patch links are provided here, consult the official Linux kernel advisories or distributions for the updated kernel versions containing this remediation.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-986c-6cjh-r8fc
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-43391"]
- Ecosystems
- []
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a9f9118acd9273b49ff2d58
Added to database: 09/08/2026, 04:37:44 UTC
Last enriched: 09/08/2026, 04:52:05 UTC
Last updated: 09/08/2026, 08:03:35 UTC
Views: 6
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