What’s Vulnerable › Vulnerabilities

CVE-2026-43403: nsfs: tighten permission checks for ns iteration ioctls

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-08 · updated 2026-06-17

Description

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 products

• Linux kernel: from 6.12 before 6.12.78; from 6.13 before 6.18.20; from 6.19 before 6.19.9; 7.0-rc1, 7.0-rc2 — fixed in 6.12.78, 6.18.20, 6.19.9

How to fix

Upgrade to a fixed version: Linux kernel 6.12.78, 6.18.20, 6.19.9. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/0ad650e60150eda789deca5e78a6a09d26bf8fc9
• https://git.kernel.org/stable/c/2f3dea284c761c890d676f77d5e55c0c496b4ef4
• https://git.kernel.org/stable/c/3376b345df155ca36d8611857b41ff7d5183fc38
• https://git.kernel.org/stable/c/e6b899f08066e744f89df16ceb782e06868bd148

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