CVE-2026-68154: Linux kernel · libceph: reject zero bucket types in crush_decode
Affects Linux kernelSource CVE Database V5
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
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 10 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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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
- git.kernel.org/stable/c/952ca5dc99913d169263f59fd689f586729a13c1 (opens in a new tab)
- git.kernel.org/stable/c/146461f09565afe3665e65b0423d3d6b0fe806c5 (opens in a new tab)
- git.kernel.org/stable/c/80fc40e11cda1b5d990a3f69c6efa344fb5cd987 (opens in a new tab)
- git.kernel.org/stable/c/b8a9fb6bf806f9c4891e71ae1beab0c07c23a877 (opens in a new tab)
- git.kernel.org/stable/c/826cd1de5802fd392922785f9b64d76e65d2a100 (opens in a new tab)
- git.kernel.org/stable/c/3b2f1937f5fce8b7dd5432e7693e3cc8b5eece56 (opens in a new tab)
- git.kernel.org/stable/c/70998f91030ee083ecb336a1dff0701c20a38081 (opens in a new tab)
- git.kernel.org/stable/c/05f90284223381005d6bcddab3fda4a97f9c3401 (opens in a new tab)