# CVE-2026-100080: Linux kernel xen-netback use-after-free in statistics

Source: https://junglewise.ai/threats/cve-2026-100080-in-the-linux-kernel-the-following-vulnerability-has-been  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-06. Updated: 2026-11-06  
License: CC BY 4.0 with a link back

CVE-2026-100080 · Severity: info · Published 2026-11-06

The Linux kernel's Xen network backend driver has a use-after-free vulnerability in how it handles network statistics data when queues are torn down during connection errors. A malicious guest with Xenstore access can cause the kernel to read freed memory, potentially exposing sensitive data or causing a denial of service on the host.

Technologies: [Linux Kernel](https://junglewise.ai/threats/technologies/kernel). Vendors: [Linux](https://junglewise.ai/threats/vendors/linux).

## Quick answers

**Is CVE-2026-100080 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-100080 being exploited in the wild.

**How severe is CVE-2026-100080?** Informational severity, published 6 November 2026.

**Which products and versions are affected?** Linux Kernel Affected versions across multiple kernel series; fix included in stable trees.

**Is there a fix for CVE-2026-100080?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-100080 attacked?** It is attacked from the adjacent network, in an operating system.

**Am I affected by CVE-2026-100080?** Check whether you run Linux Kernel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a use-after-free (UAF) in the xen-netback driver's statistics data handling. Network statistics are protected by RCU synchronization, but during queue teardown following a connection error, the statistics data is freed without calling synchronize_net() to wait for in-flight RCU readers. If sysfs reads the statistics during this window, they access already-freed memory. The fix adds synchronize_net() before queue deinitialization to ensure all RCU readers have completed.

## Affected products

- Linux Linux kernel Affected versions across multiple kernel series; fix included in stable trees

## Timeline

- 2026-11-06: disclosed

## References

- [https://git.kernel.org/stable/c/36f858f228e3f955b9336af7f94634747c221518](https://git.kernel.org/stable/c/36f858f228e3f955b9336af7f94634747c221518)
- [https://git.kernel.org/stable/c/37d5a73170579b30e67cc8b19ec69715eea3a6b6](https://git.kernel.org/stable/c/37d5a73170579b30e67cc8b19ec69715eea3a6b6)

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