CVE-2026-46159

Medium

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix btrfs_ioctl_space_info() slot_count TOCTOU which can lead to info-leak btrfs_ioctl_space_info() has a TOCTOU race between two passes over the block group RAID type lists. The first pass counts entries to determine the allocation size, then the second pass fills the buffer. The groups_sem rwlock is released between passes, allowing concurrent block group removal to reduce the entry count. When the second pass fills fewer entries than the first pass counted, copy_to_user() copies the full alloc_size bytes including trailing uninitialized kmalloc bytes to userspace. Fix by copying only total_spaces entries (the actually-filled count from the second pass) instead of alloc_size bytes, and switch to kzalloc so any future copy size mismatch cannot leak heap data.

Package Linux Kernel
Published 2026-05-28
Last modified 2026-06-19
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

4.7

out of 10
Medium
Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-367

CVE-2026-46159 is classified as CWE-367

See CWE-367 on MITRE CWE for full details on this weakness type.

Affected versions

Linux kernel versions 2.6.34 and later are affected. Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.140, 6.12.90, 6.18.32, 7.0.7, 7.1 and their respective stable series.

Affected from
≥ 2.6.34
Fixed in
✓ 5.10.259 5.10.x ✓ 5.15.210 5.15.x ✓ 6.1.176 6.1.x ✓ 6.6.140 6.6.x ✓ 6.12.90 6.12.x ✓ 6.18.32 6.18.x ✓ 7.0.7 7.0.x ✓ 7.1

References

8 total
Showing 5 of 8 references View all on NVD

Frequently asked questions

  • What is CVE-2026-46159?

    CVE-2026-46159 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10 . It affects Linux kernel versions from 2.6.34 onward and has been patched in 5.10.259, 5.15.210, 6.1.176 and others. CVE-2026-46159 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-46159?

    CVE-2026-46159 has a CVSS score of 4.7 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2026-46159?

    Yes. CVE-2026-46159 has been patched. Fixed versions include 5.10.259, 5.15.210, 6.1.176 and others. If you are running Linux kernel 2.6.34 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-46159 actively exploited?

    No. CVE-2026-46159 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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