Medium [CVE-2026-89560] Linux kernel (Landlock): Security bypass via improper whiteout creation permissions
This medium-severity Red Hat Linux advisory covers CVE-2026-89560 affecting Red Hat OpenShift Container Platform 4.
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Summary
A flaw was found in the Linux kernel's Landlock security module. This vulnerability allowed for the creation of 'whiteout' objects without proper permission checks.
Whiteout objects are special files used in OverlayFS to hide underlying files, and their unauthorized creation could lead to unexpected file system behavior or bypass security restrictions. A local attacker could exploit this by using specific mknod(2) or renameat2(2) system calls.
Red Hat severity: Moderate — CVSS 5.3 (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H). Weakness: CWE-1220.
Affected Red Hat products: Red Hat OpenShift Container Platform 4. Red Hat does not currently list a fixing RHSA for this CVE.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 20 minutes ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 20 minutes ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 20 minutes ago·verify at source
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