---
id: "CVE-2026-100080"
page: "https://infrastack.ai/live/CVE-2026-100080"
kind: "vulnerability"
aliases: ["CVE-2026-100080"]
title: "Linux kernel: xen-netback use-after-free when reading network statistics"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "linux-kernel", "xen", "xen-netback"]
not_affected_if: ["no-xen", "xen-netback-not-loaded"]
published_at: "2026-11-06T19:17:03+00:00"
first_seen_at: "2026-11-06T19:43:47+00:00"
updated_at: "2026-11-06T19:46:22+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-100080", "first_seen_at": "2026-11-06T19:43:47+00:00"}]
exploit_sources: []
---

# Linux kernel: xen-netback use-after-free when reading network statistics

Link for people: https://infrastack.ai/live/CVE-2026-100080 (this .md is for agents)

In the Linux kernel's xen-netback driver, network statistics can be read through sysfs after queue teardown has freed the data without waiting for RCU. This leads to reads of freed or reused memory.

_Summary, check and fix written by a model from the sources; labelled as such._

## Timeline

- 2026-11-06T19:43:47+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-100080

## From the sources

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

xen-netback: Fix UAF when reading statistics data

The network statistic data in the driver is protected by RCU.
Unfortunately when tearing down the queues after an error during
connecting to the frontend (e.g. due to illegal Xenstore data filled
in by the guest), the statistic data is being freed without
synchronizing the RCU state.  In case the data is being read via sysfs
in this phase, access to already freed memory or memory being in new
use is possible.

Fix that by calling synchronize_net() before freeing the queue data.

This is XSA-526 / CVE-2026-100080

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_