Linux Kernel up to 6.19.8 nsfs may_see_all_namespaces permission

CVSS Meta Temp Score
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CTI Interest Score
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8.2$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.19.8 and classified as critical. Affected is the function may_see_all_namespaces of the component nsfs. Such manipulation leads to permission. This vulnerability is referenced as CVE-2026-43391. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.19.8. It has been rated as critical. Affected by this issue is the function may_see_all_namespaces of the component nsfs. The manipulation with an unknown input leads to a permission vulnerability. Using CWE to declare the problem leads to CWE-275. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-43391 since 05/01/2026. The exploitation is known to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 05/27/2026). The MITRE ATT&CK project declares the attack technique as T1222.

Upgrading to version 6.19.9 eliminates this vulnerability. Applying the patch 1797ee11451f1b2be69863a9f5bd43b948813fdf/d2324a9317f00013facb0ba00b00440e19d2af5e is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.4
VulDB Meta Temp Score: 8.2

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.8
CNA Vector (Linux): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Permission
CWE: CWE-275 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.19.9
Patch: 1797ee11451f1b2be69863a9f5bd43b948813fdf/d2324a9317f00013facb0ba00b00440e19d2af5e

Timelineinfo

05/01/2026 CVE reserved
05/08/2026 +7 days Advisory disclosed
05/08/2026 +0 days VulDB entry created
05/27/2026 +19 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-43391 (🔒)
GCVE (CVE): GCVE-0-2026-43391
GCVE (VulDB): GCVE-100-362240

Entryinfo

Created: 05/08/2026 18:30
Updated: 05/27/2026 13:01
Changes: 05/08/2026 18:30 (59), 05/27/2026 13:01 (11)
Complete: 🔍
Cache ID: 216::103

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