---
id: "CVE-2026-99287"
page: "https://infrastack.ai/live/CVE-2026-99287"
kind: "vulnerability"
aliases: ["CVE-2026-99287"]
title: "Linux kernel xen-netback: double unmap of ring pointers on connect failure"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "linux-kernel", "xen", "xen-netback"]
not_affected_if: []
published_at: "2026-11-10T19:22:32+00:00"
first_seen_at: "2026-11-10T19:25:35+00:00"
updated_at: "2026-11-10T20:04:40+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99287", "first_seen_at": "2026-11-10T19:25:35+00:00"}]
exploit_sources: []
---

# Linux kernel xen-netback: double unmap of ring pointers on connect failure

Link for people: https://infrastack.ai/live/CVE-2026-99287 (this .md is for agents)

When mapping the frontend data rings fails after one ring is already mapped, the xen-netback driver unmaps them and then unmaps the same pointers again during cleanup. The sources do not state what an attacker gets from the second unmap.

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

## Timeline

- 2026-11-10T19:25:35+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-99287

## From the sources

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

xen-netback: Zero out sring pointers on unmap

If xenvif_map_frontend_data_rings() fails when a ring is already mapped,
it unmaps them via xenvif_unmap_frontend_data_rings() which keeps the
ring pointers unchanged. xenvif_connect_data()'s cleanup path calls
xenvif_disconnect_queue() which in turn calls
xenvif_unmap_frontend_data_rings() again, which will attempt to unmap the
pointers a second time.

Zero out the ring pointers after they are unmapped to avoid this issue.

This is XSA-532

---

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