CVE-2026-68442

Last refreshed2026-10-17

Status: UPDATED | Advisory ID: CVE-2026-68442

Key Details

CVE	CVE-2026-68442
CVSS Score / Version	7.8 (High) / CVSS v3.1
Updated	2026-10-16
CVSS Vector	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`
CVSS Prose	attack vector is local; attack complexity is low; privileges required is low; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high.
Affected products	Linux Kernel

Vendor	Product	Affected Versions	Patch Status
Linux	Linux Kernel

Vendor

Product

Affected Versions

Patch Status

Linux

Linux Kernel

Subsystems	OT Supporting Infrastructure
Sectors	All Sectors

In the Linux kernel, the following vulnerability has been resolved:

btrfs: don't propagate EXTENT_FLAG_LOGGING to split extent maps

When btrfs_drop_extent_map_range() splits an extent map, the new split

maps inherit the original map's flags through a local 'flags' variable.

Commit f86f7a75e2fb ("btrfs: use the flags of an extent map to identify

the compression type") changed the EXTENT_FLAG_LOGGING clearing to

operate on em->flags instead of that local 'flags' copy, so a split of

an extent map that is currently being logged wrongly inherits

EXTENT_FLAG_LOGGING.

The flag is then never cleared on the split, and when it is freed while

still on the inode's modified_extents list (for example by the extent

map shrinker) it trips the WARN_ON(!list_empty(&em->list)) in

btrfs_free_extent_map() and leads to a use-after-free.

Clear EXTENT_FLAG_LOGGING from the local 'flags' copy used for the

splits and only clear EXTENT_FLAG_PINNED from em->flags, restoring the

behaviour prior to f86f7a75e2fb. (NVD)

Monitor Linux's web page for any future patch releases.

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-68442
CVE	https://www.cve.org/CVERecord?id=CVE-2026-68442

Source

Reference

NVD

CVE