CVE-2026-89560
Last modified
CVE-2026-89560 is a high-severity vulnerability rated 8.4/10 on the CVSS scale. 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. EPSS estimates a 0.12% chance of exploitation in the next 30 days.
Description
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]
Metrics
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= cb2c7d1a1776057c9a1f48ed1250d85e94d4850d, < d739e32318479086efb8a6bcf5d37cf341b51f8f; >= cb2c7d1a1776057c9a1f48ed1250d85e94d4850d, < dfb10d989056181168ebc16781a8f39520e33200; >= cb2c7d1a1776057c9a1f48ed1250d85e94d4850d, < efb4f24fc2b9bcef1c41ff3392894f1fa8fba2a0; >= cb2c7d1a1776057c9a1f48ed1250d85e94d4850d, < 627ce4902df1d737e99306daae5a87c68b876d16; >= cb2c7d1a1776057c9a1f48ed1250d85e94d4850d, < 0c3204aacbe8c07f9e87e3028f28ec6c166a1075; >= cb2c7d1a1776057c9a1f48ed1250d85e94d4850d, < 672fa082d48b21e1fb62cdb184fee41513e53421 |
| Linux | Linux | 5.13 |
References
Timeline
- Published
- Last Modified
- Status
- Received
Frequently Asked Questions
What is CVE-2026-89560?
How severe is CVE-2026-89560?
How do I fix CVE-2026-89560?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-89555In the Linux kernel, the following vulnerability has been re…9.8
- CVE-2026-89556In the Linux kernel, the following vulnerability has been re…
- CVE-2026-89557In the Linux kernel, the following vulnerability has been re…7.8
- CVE-2026-89558In the Linux kernel, the following vulnerability has been re…9.8
- CVE-2026-89559In the Linux kernel, the following vulnerability has been re…7.8
- CVE-2026-8956Integer overflow in the Networking: JAR component. This vuln…9.8
- CVE-2026-89561In the Linux kernel, the following vulnerability has been re…7.5
- CVE-2026-89562In the Linux kernel, the following vulnerability has been re…7.8
- CVE-2026-89563In the Linux kernel, the following vulnerability has been re…7.8
- CVE-2026-89564In the Linux kernel, the following vulnerability has been re…7.8
- CVE-2026-89565In the Linux kernel, the following vulnerability has been re…
- CVE-2026-89566In the Linux kernel, the following vulnerability has been re…
Are you affected by CVE-2026-89560?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST
