CyberSecBulletin
CVE-2026-68154NVD status: Received

In the Linux kernel, the following vulnerability has been resolved: libceph: reject zero…

Published Updated By the CyberSecBulletin desk

CVE-2026-68154 is a critical-severity improper input validation vulnerability in Linux, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 952ca5dc99913d169263f59fd689f586729a13c1, 146461f09565afe3665e65b0423d3d6b0fe806c5, 80fc40e11cda1b5d990a3f69c6efa344fb5cd987 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.71% chance of exploitation within 30 days, higher than 54% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Linux to 952ca5dc99913d169263f59fd689f586729a13c1 or 146461f09565afe3665e65b0423d3d6b0fe806c5 or 80fc40e11cda1b5d990a3f69c6efa344fb5cd987 or b8a9fb6bf806f9c4891e71ae1beab0c07c23a877, whichever matches your release line, or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxf24e9980eb860d8600cbe5ef3d2fd9295320d229 up to, but not including, 952ca5dc99913d169263f59fd689f586729a13c1; f24e9980eb860d8600cbe5ef3d2fd9295320d229 up to, but not including, 146461f09565afe3665e65b0423d3d6b0fe806c5; f24e9980eb860d8600cbe5ef3d2fd9295320d229 up to, but not including, 80fc40e11cda1b5d990a3f69c6efa344fb5cd987; f24e9980eb860d8600cbe5ef3d2fd9295320d229 up to, but not including, b8a9fb6bf806f9c4891e71ae1beab0c07c23a877; f24e9980eb860d8600cbe5ef3d2fd9295320d229 up to, but not including, 826cd1de5802fd392922785f9b64d76e65d2a100; f24e9980eb860d8600cbe5ef3d2fd9295320d229 up to, but not including, 3b2f1937f5fce8b7dd5432e7693e3cc8b5eece56; f24e9980eb860d8600cbe5ef3d2fd9295320d229 up to, but not including, 70998f91030ee083ecb336a1dff0701c20a38081; f24e9980eb860d8600cbe5ef3d2fd9295320d229 up to, but not including, 05f90284223381005d6bcddab3fda4a97f9c3401; and 1 more ranges952ca5dc99913d169263f59fd689f586729a13c1, 146461f09565afe3665e65b0423d3d6b0fe806c5, 80fc40e11cda1b5d990a3f69c6efa344fb5cd987, b8a9fb6bf806f9c4891e71ae1beab0c07c23a877, 826cd1de5802fd392922785f9b64d76e65d2a100, 3b2f1937f5fce8b7dd5432e7693e3cc8b5eece56

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How developers prevent this class of flaw

  • Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
  • Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.

More Improper Input Validation vulnerabilities (CWE-20)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Improper Input Validation vulnerabilities

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