CVE-2026-43403
published 2026-05-08CVE-2026-43403: In the Linux kernel, the following vulnerability has been resolved: nsfs: tighten permission checks for ns iteration ioctls Even privileged services should not…
PriorityP343high8.8CVSS 3.1
AVLACLPRLUINSCCHIHAH
EPSS
0.13%
2.9th percentile
In the Linux kernel, the following vulnerability has been resolved:
nsfs: tighten permission checks for ns iteration ioctls
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
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | >= a1d220d9dafa8d76ba60a784a1016c3134e6a1e8 < 3376b345df155ca36d8611857b41ff7d5183fc38 | 3376b345df155ca36d8611857b41ff7d5183fc38 |
| linux | linux | >= a1d220d9dafa8d76ba60a784a1016c3134e6a1e8 < 2f3dea284c761c890d676f77d5e55c0c496b4ef4 | 2f3dea284c761c890d676f77d5e55c0c496b4ef4 |
| linux | linux | >= a1d220d9dafa8d76ba60a784a1016c3134e6a1e8 < 0ad650e60150eda789deca5e78a6a09d26bf8fc9 | 0ad650e60150eda789deca5e78a6a09d26bf8fc9 |
| linux | linux | >= a1d220d9dafa8d76ba60a784a1016c3134e6a1e8 < e6b899f08066e744f89df16ceb782e06868bd148 | e6b899f08066e744f89df16ceb782e06868bd148 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 6.12 < 6.12.78 | 6.12.78 |
| linux | linux_kernel | >= 6.13 < 6.18.20 | 6.18.20 |
| linux | linux_kernel | >= 6.19 < 6.19.9 | 6.19.9 |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
vendor_redhat7.0MEDIUM
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VulDB
Linux Kernel up to 6.12.77/6.18.19/6.19.8 nsfs may_see_all_namespaces permission (Nessus ID 313431)
vuldb·2026-05-22·CVSS 8.8
CVE-2026-43403 [HIGH] Linux Kernel up to 6.12.77/6.18.19/6.19.8 nsfs may_see_all_namespaces permission (Nessus ID 313431)
A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.12.77/6.18.19/6.19.8. This vulnerability affects the function may_see_all_namespaces of the component nsfs. The manipulation results in permission issues.
This vulnerability is cataloged as CVE-2026-43403. The attack must originate from the local network. There is no exploit available.
It is advisable to upgrade the affected component.
GHSA
GHSA-6ghr-3376-w3mq: In the Linux kernel, the following vulnerability has been resolved:
nsfs: tighten permission checks for ns iteration ioctls
Even privileged services
ghsa_unreviewed·2026-05-08
CVE-2026-43403 GHSA-6ghr-3376-w3mq: In the Linux kernel, the following vulnerability has been resolved:
nsfs: tighten permission checks for ns iteration ioctls
Even privileged services
In the Linux kernel, the following vulnerability has been resolved:
nsfs: tighten permission checks for ns iteration ioctls
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.
Red Hat
kernel: nsfs: tighten permission checks for ns iteration ioctls
vendor_redhat·2026-05-08·CVSS 7.0
CVE-2026-43403 [MEDIUM] CWE-280 kernel: nsfs: tighten permission checks for ns iteration ioctls
kernel: nsfs: tighten permission checks for ns iteration ioctls
A flaw was found in the Linux kernel's `nsfs` component. This vulnerability allows privileged services to bypass permission checks related to namespace iteration input/output controls (ioctls). As a result, one privileged service could potentially view information from other privileged services, leading to unauthorized information disclosure.
Package: kernel (Red Hat Enterprise Linux 10) - Affected
Package: kernel (Red Hat Enterprise Linux 6) - Not affected
Package: kernel (Red Hat Enterprise Linux 7) - Not affected
Package: kernel-rt (Red Hat Enterprise Linux 7) - Not affected
Package: kernel (Red Hat Enterprise Linux 8) - Not affected
Package: kernel-rt (Red Hat Enterprise Linux 8) - Not affected
Package: kernel (Red
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-43403 kernel: nsfs: tighten permission checks for ns iteration ioctls
bugzilla·2026-05-08
CVE-2026-43403 [MEDIUM] CVE-2026-43403 kernel: nsfs: tighten permission checks for ns iteration ioctls
CVE-2026-43403 kernel: nsfs: tighten permission checks for ns iteration ioctls
In the Linux kernel, the following vulnerability has been resolved:
nsfs: tighten permission checks for ns iteration ioctls
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.
Discussion:
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050840-CVE-2026-43403-3869@gregkh/T
Wiz
CVE-2025-43403 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 8.8
CVE-2025-43403 [HIGH] CVE-2025-43403 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2025-43403 :
macOS vulnerability analysis and mitigation
An authorization issue was addressed with improved state management. This issue is fixed in macOS Sequoia 15.7.4, macOS Sonoma 14.8.4. An app may be able to access sensitive user data.
Source : NVD
## 5.5
Score
Published February 11, 2026
Severity MEDIUM
CNA Score 5.5
Affected Technologies
macOS
Has Public Exploit No
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 1.6
Exploitation Probability (EPSS) N/A
Affected packages and libraries
Compression
Sources
NVD
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CVE
2026-05-08
Published