CVE intelligence

CVE-2026-93798

Vulnerability intelligence

Published Sep 24, 2026Sources checked Nov 12, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-93798 and is rated High severity with a CVSS score of 7.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Oct 15, 2026

Release Notes

Vendor-listed releases

6.6.158.1-1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.1%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-93798?

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

btrfs: fix reloc root cleanup in merge_reloc_roots()

If the root we got has zero root refs in its root item, we are resetting the root's ->reloc_root without using barriers like we do everywhere else. Sashiko complained about this while reviewing another patch, and it's correct (see the Link tag below).

Also, we should not clear BTRFS_ROOT_DEAD_RELOC_TREE from the root unless the root points to the reloc root we have.

Fix this by using clear_reloc_root(), which issues the memory barrier after setting the root's ->reloc_root to NULL and before clearing the bit BTRFS_ROOT_DEAD_RELOC_TREE from the root.

Source: NVD