CVE intelligence

CVE-2026-100081

Vulnerability intelligence

Published Nov 6, 2026Sources checked Nov 10, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-100081 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: Nov 9, 2026

Release Notes

CISA KEVNot listedBased on the latest collected catalog

EPSS0.2%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-100081?

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

xen-netback: defer xenvif_mcast_addr_list_free()

In order for the function to legitimately avoid locking/RCU, it needs to run after all TX/RX processing has finished/stopped: Lookups happen from xenvif_start_xmit(), while adds/removes happen from xenvif_tx_action() (called out of xenvif_poll()).

Move the call out of xenvif_disconnect_data() (the call to the function from connect()'s error path doesn't require any cleaning up there), and put it past the synchronization point in backend_disconnect().

This is XSA-527 / CVE-2026-100081.

Source: NVD