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VulnerabilityPublished Updated

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

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 9.8 Critical · fixed in b8a9fb6bf806f9c4891e71ae1beab0c07c23a877 : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers can reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in b8a9fb6bf806f9c4891e71ae1beab0c07c23a877, 146461f09565afe3665e65b0423d3d6b0fe806c5, 70998f91030ee083ecb336a1dff0701c20a38081 +5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < b8a9fb6bf806f9c4891e71ae1beab0c07c23a877
Fixed in
  • b8a9fb6bf806f9c4891e71ae1beab0c07c23a877
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < 146461f09565afe3665e65b0423d3d6b0fe806c5
Fixed in
  • 146461f09565afe3665e65b0423d3d6b0fe806c5
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < 70998f91030ee083ecb336a1dff0701c20a38081
Fixed in
  • 70998f91030ee083ecb336a1dff0701c20a38081
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < 952ca5dc99913d169263f59fd689f586729a13c1
Fixed in
  • 952ca5dc99913d169263f59fd689f586729a13c1
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < 826cd1de5802fd392922785f9b64d76e65d2a100
Fixed in
  • 826cd1de5802fd392922785f9b64d76e65d2a100
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < 80fc40e11cda1b5d990a3f69c6efa344fb5cd987
Fixed in
  • 80fc40e11cda1b5d990a3f69c6efa344fb5cd987

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.

References

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