Review reviewHigh

CVE-2026-46107

Linux Linux, linux kernel

In the Linux kernel, the following vulnerability has been resolved: dm-thin: fix metadata refcount underflow There's a bug in dm-thin in the function rebalance_children. If the internal btree node has one entry, the code tries to copy all btree entries from the node's child to the node itself and then decrement the child's reference count. If the child node is shared (it has reference count > 1), we won't free it, so there would be two pointers to each of the grandchildren nodes. But the reference counts of the grandchildren is not increased, thus the reference count doesn't match the numbe...

CVSS
7.8
EPSS
0.13%
2.96% percentile
CISA KEV
Not listed
Published
2026.05.28
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.13%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: dm-thin: fix metadata refcount underflow There's a bug in dm-thin in the function rebalance_children. If the internal btree node has one entry, the code tries to copy all btree entries from the node's child to the node itself and then decrement the child's reference count. If the child node is shared (it has reference count > 1), we won't free it, so there would be two pointers to each of the grandchildren nodes. But the reference counts of the grandchildren is not increased, thus the reference count doesn't match the numbe...

Affected product and versions

Product
Linux Linux, linux kernel
Affected versions
3241b1d3e0aaafbfcd320f4d71ade629728cc4f4, 3.2, >= 3.2 < 5.10.259, >= 5.11 < 5.15.209, >= 5.16 < 6.1.175, >= 6.2 < 6.6.140, >= 6.7 < 6.12.88, >= 6.13 < 6.18.30, >= 6.19 < 7.0.7, 7.1
Fixed versions
5.10.259, 5.15.209, 6.1.175, 6.6.140, 6.12.88, 6.18.30, 7.0.7

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, linux kernel and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-191
CVE-2026-46107 — Linux Linux, linux kernel | SECUFOCUS NOW