What’s Vulnerable › Vulnerabilities

CVE-2026-68154: libceph: reject zero bucket types in crush_decode

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-10 · updated 2026-10-19
• Weakness: CWE-20

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.

Affected products

• Linux kernel: 2.6.34 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/05f90284223381005d6bcddab3fda4a97f9c3401
• https://git.kernel.org/stable/c/146461f09565afe3665e65b0423d3d6b0fe806c5
• https://git.kernel.org/stable/c/3b2f1937f5fce8b7dd5432e7693e3cc8b5eece56
• https://git.kernel.org/stable/c/70998f91030ee083ecb336a1dff0701c20a38081
• https://git.kernel.org/stable/c/80fc40e11cda1b5d990a3f69c6efa344fb5cd987
• https://git.kernel.org/stable/c/826cd1de5802fd392922785f9b64d76e65d2a100
• https://git.kernel.org/stable/c/952ca5dc99913d169263f59fd689f586729a13c1
• https://git.kernel.org/stable/c/b8a9fb6bf806f9c4891e71ae1beab0c07c23a877

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