CVE-2026-89560

What it is

In the Linux kernel, the following vulnerability has been resolved: landlock: Require LANDLOCK_ACCESS_FS_MAKE_REG for whiteout creation Whiteout objects are used in the upper layer of an OverlayFS to indicate that the file with this name does not exist in the unified view, even if it is present in one of the lower layer file systems. For the userspace implementations of OverlayFS (fuse-overlayfs), whiteout objects can be created from userspace as well: * mknod(2) with S_IFCHR and makedev(0, 0) * renameat2(2) with RENAME_WHITEOUT, creating the whiteout in the old place of the moved file. This commit guards whiteout creation in both of these cases with LANDLOCK_ACCESS_FS_MAKE_REG. Whiteout objects are *not* considered character devices and are not bound to a driver. LANDLOCK_ACCESS_FS_MAKE_REG describes the same permission class as a whiteout object: creating one is the only S_IFCHR creation that the VFS exempts from CAP_MKNOD, so it is as unprivileged as creating a regular file, while LANDLOCK_ACCESS_FS_MAKE_CHAR and LANDLOCK_ACCESS_FS_MAKE_BLOCK keep meaning the creation of devices that expose a kernel interface [1]. For the mknod(2) case, introduce a Landlock erratum. The creation of whiteout objects through mknod(2) was previously guarded using LANDLOCK_ACCESS_FS_MAKE_CHAR, and it is now guarded using LANDLOCK_ACCESS_FS_MAKE_REG. For the renameat2(2) case, fix a bug: Before this commit, renameat2(2) with RENAME_WHITEOUT would create a directory entry even when all LANDLOCK_ACCESS_FS_MAKE_* rights were denied. This does not affect normal renames within layered OverlayFS mounts: When doing a regular rename() on a mounted fuse-overlayfs, it is the fuse-overlayfs daemon that exercises renameat2() with RENAME_WHITEOUT, and only the Landlock domain of that daemon is checked there. Depends-on: 49c9e09d9610 ("landlock: Fix handling of disconnected directories") Depends-on: fe72ce6710cb ("landlock: Add errata documentation section") [mic: Record why LANDLOCK_ACCESS_FS_MAKE_REG is the matching right, and add link(2) to the user doc]

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data tampering, service disruption.

Exploit odds

0.1% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-09-11 19:38 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-09-11 20:19 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-10-19 09:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.1% in the next 30 days (EPSS).
• Severity: 8.4 HIGH (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2026-09-11 20:19 UTC

Last modified

2026-10-19 09:17 UTC

Exploit probability

0.1% · EPSS, next 30 days

Record status

Received

Attack profile CVSS 3.1 · 8.4

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Changed

Confidentiality

None

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-89560.md and follow it. Check whether this project is affected by CVE-2026-89560. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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