CVE-2026-31666

Last refreshed2026-10-17

Status: UPDATED | Advisory ID: CVE-2026-31666

Key Details

CVE	CVE-2026-31666
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: fix incorrect return value after changing leaf in lookup_extent_data_ref()

After commit 1618aa3c2e01 ("btrfs: simplify return variables in

lookup_extent_data_ref()"), the err and ret variables were merged into

a single ret variable. However, when btrfs_next_leaf() returns 0

(success), ret is overwritten from -ENOENT to 0. If the first key in

the next leaf does not match (different objectid or type), the function

returns 0 instead of -ENOENT, making the caller believe the lookup

succeeded when it did not. This can lead to operations on the wrong

extent tree item, potentially causing extent tree corruption.

Fix this by returning -ENOENT directly when the key does not match,

instead of relying on the ret variable. (NVD)

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

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-31666
CVE	https://www.cve.org/CVERecord?id=CVE-2026-31666

Source

Reference

NVD

CVE