CVE-2026-68154 libceph: reject zero bucket types in crush_decode
A malformed CRUSH map can cause a negative array index in the Linux kernel, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68154?
CVE-2026-68154 is a critical vulnerability in Linux, published on 10 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
libceph: reject zero bucket types in crush_decode
CRUSH bucket type 0 is reserved for devices. The mapper relies on that invariant and uses type 0 to identify leaf devices.
If crush_decode() accepts a bucket with type 0, a malformed CRUSH map can make the mapper treat a negative bucket ID as a device and pass it to is_out(), which then indexes the OSD weight array with a negative value.
Reject zero bucket types while decoding the CRUSH map so the invalid state never reaches the mapper.
Weakness: CWE-20
Which versions are affected by CVE-2026-68154?
How do I fix CVE-2026-68154?
Apply the vendor's patch.
Is CVE-2026-68154 being exploited?
There is no known exploitation of CVE-2026-68154 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68154, DEBIAN-CVE-2026-68154, GHSA-33w3-5969-wxfc, UBUNTU-CVE-2026-68154.