CVE-2026-43390
📛 CVE Title
nstree: tighten permission checks for listing
Description
In the Linux kernel, the following vulnerability has been resolved: nstree: tighten permission checks for listing 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.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- Linux
- CVSS severity
- high
- CVSS score
- 7.1 / 10
- CVSS vector
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H- Effective score
- 7.1 / 10 HIGH source: CNA overview
- CWE(s)
- —
- Reserved
- 2026-05-01
- Published
- 2026-05-08 16:21 UTC
- Last updated
- 2026-05-12 00:23 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/43xxx/CVE-2026-43390.json
- Linked Threat
- CVE-2026-43390 — CVE-2026-43390
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-05-08 15:16:50 UTC
- NVD last modified
- 2026-05-12 14:10:27 UTC
- EPSS score
- 0.0002 (probability of exploitation in next 30 days)
- EPSS percentile
- 7.14% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 08:56 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-28696 - Assigner
- Linux
- Published
- May 8, 2026, 2:21:35 PM
- Updated
- May 11, 2026, 10:23:39 PM
- EUVD base score
- 0.0 / 10
- EUVD-reported EPSS
- 0.0100
- Vendors
- Linux
- Products
-
Linux (76b6f5dfb3fda76fce1f9990d6fa58adc711122b <8d76afe84fa2babf604b3c173730d4d2b067e361)Linux (76b6f5dfb3fda76fce1f9990d6fa58adc711122b <0abd81645fc95ec6a9d4e4813000f22c5efc0ff4)Linux (patch: 7.0)Linux (patch: 0)Linux (6.19)Linux (patch: 6.19.9)
ENISA description: In the Linux kernel, the following vulnerability has been resolved: nstree: tighten permission checks for listing 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.
Affected products (2)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| Linux | Linux |
76b6f5dfb3fda76fce1f9990d6fa58adc711122b (affected),
76b6f5dfb3fda76fce1f9990d6fa58adc711122b (affected)
|
— |
| Linux | Linux |
6.19 (affected),
0 (unaffected),
6.19.9 (unaffected),
7.0 (unaffected)
|
— |
Vendor references (2)
References embedded in the original CVE record by the assigning CNA.
MITRE references (2) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
Web references (3)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- https://nvd.nist.gov/vuln/detail/CVE-2026-43390 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-43390 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
NVD-tagged references (2)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://git.kernel.org/stable/c/0abd81645fc95ec6a9d4e4813000f22c5efc0ff4 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/8d76afe84fa2babf604b3c173730d4d2b067e361 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remediations (18)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:attack.mitre.org
This mitigation can be implemented through the following measures: Regular Operating System Updates Implementation: Apply the latest Windows security updates monthly using WSUS (Windows Server Update Services) or a similar patch management solution. Configure systems to check for updates automatically and schedule reboots during maintenance ...
2026-05-23 21:05 UTC -
web:blog.qualys.com
With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.
2026-05-23 21:05 UTC -
web:blogs.oracle.com
For more information about the Critical Patch Update program, see the security vulnerability remediation practices page located on the Oracle Trust Center.
2026-05-23 21:05 UTC -
web:krebsonsecurity.com
For a clickable, per- patch breakdown, check out the SANS Internet Storm Center Patch Tuesday roundup. Running into problems applying any of these updates?
2026-05-23 21:05 UTC -
web:layerlogix.com
April 2026 Patch Tuesday drops today. Here's what's critical, what to patch first, and how Houston IT teams should handle deployment — including the Secure Boot certificate deadline reminder.
2026-05-23 21:05 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-05-23 21:05 UTC -
web:redmondmag.com
Microsoft April 2026 Patch Tuesday fixed 163 CVEs , marking its second-largest security update. Three zero-day vulnerabilities impacted SharePoint, Chromium-based Edge workflows and Microsoft Defender.
2026-05-23 21:05 UTC -
web:www.bleepingcomputer.com
Today is Microsoft's April 2026 Patch Tuesday with security updates for 167 flaws, including 2 zero-day vulnerabilities.
2026-05-23 21:05 UTC -
web:www.crowdstrike.com
Microsoft's April 2026 Patch Tuesday addresses 164 CVEs , featuring 8 Critical vulnerabilities, one exploited zero-day, and one disclosed zero-day.
2026-05-23 21:05 UTC -
web:www.zafran.io
Mitigation is the control implemented or the action taken to reduce the impact or likelihood of a vulnerability or exposure being exploited before a fix is available or applied. Remediation is the resolution of the vulnerability or exposure which is completed typically through applying patches, updates, or correcting misconfigurations.
2026-05-23 21:05 UTC -
web:access.redhat.com
Learn about our open source products, services, and company. You are here
2026-05-26 02:48 UTC -
web:blog.qualys.com
Oracle released its second quarterly edition of this year's Critical Patch Update. The update received patches for 481 security vulnerabilities.
2026-05-26 02:48 UTC -
web:community.ui.com
Published: May 21, 2026 Updated: May 22, 2026 Version: 1.1 Revision: 1.1 Summary 1 of 5 A malicious actor with access to the network and high privileges could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection. Affected Products: UniFi OS Server (Version 5.0.6 and earlier) Mitigation : Update your UniFi OS Server to Version 5.0.8 or later ...
2026-05-26 02:48 UTC -
web:cyberpress.org
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .
2026-05-26 02:48 UTC -
web:msrc.microsoft.com
The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.
2026-05-26 02:48 UTC -
web:nvd.nist.gov
An official website of the United States government Here's how you know
2026-05-26 02:48 UTC -
web:support.servicenow.com
Overview The advisories below document publicly disclosed Common Vulnerabilities and Exposures ( CVEs ) in the Now Platform by ServiceNow. Because ServiceNow uses various methods to communicate vulnerability information, patches, and other fixes, customers should review family, security patch , and hotfix release notes, which are available at https://docs.servicenow.com, for a complete list of ...
2026-05-26 02:48 UTC -
web:www.oracle.com
This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.
2026-05-26 02:48 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-43390.json.
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"product": "Linux",
"programFiles": [
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"vendor": "Linux",
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{
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"status": "affected",
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},
{
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"status": "affected",
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}
]
},
{
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"versions": [
{
"status": "affected",
"version": "6.19"
},
{
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},
{
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},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
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"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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}
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{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnstree: tighten permission checks for listing\n\nEven privileged services should not necessarily be able to see other\nprivileged service's namespaces so they can't leak information to each\nother. Use may_see_all_namespaces() helper that centralizes this policy\nuntil the nstree adapts."
}
],
"providerMetadata": {
"dateUpdated": "2026-05-11T22:23:39.579Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
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"references": [
{
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},
{
"url": "https://git.kernel.org/stable/c/8d76afe84fa2babf604b3c173730d4d2b067e361"
}
],
"title": "nstree: tighten permission checks for listing",
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"cveId": "CVE-2026-43390",
"datePublished": "2026-05-08T14:21:35.337Z",
"dateReserved": "2026-05-01T14:12:56.007Z",
"dateUpdated": "2026-05-11T22:23:39.579Z",
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