---
id: "CVE-2026-99169"
kind: "vulnerability"
aliases: ["CVE-2026-99169"]
title: "Linux kernel: futex wakeups can reach the wrong process memory"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["kernel", "linux", "multi-threaded", "runtime"]
not_affected_if: []
published_at: "2026-10-28T11:17:37+00:00"
first_seen_at: "2026-10-28T11:32:36+00:00"
updated_at: "2026-10-28T11:35:37+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99169", "first_seen_at": "2026-10-28T11:32:36+00:00"}]
---

# Linux kernel: futex wakeups can reach the wrong process memory

A shared futex can be requeued onto a memory map that has been freed, so waiters on a freed mm consume wakeups meant for a newly allocated mm at the same address. The fix keys shared futexes by a unique 64-bit per-mm ID instead of the address.

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

## How to check

- unknown

## Fix

- unknown

## Timeline

- 2026-10-28T11:32:36+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-99169

## From the sources

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

futex: Fix mm reuse handling for FUT_OFF_MMSHARED

A FUT_OFF_MMSHARED futex is a shared futex that refers to an MM.
It is possible for a process to wait on a shared futex with a different MM
because a FUT_OFF_INODE waiter can be requeued onto a FUT_OFF_MMSHARED
futex by another process.
This can cause FUT_OFF_MMSHARED waiters on a freed MM to consume
wakeups intended for a newly allocated MM at the same address.

Fix it by keying FUT_OFF_MMSHARED using a unique 64-bit per-MM ID.
Leave private futexes as before to avoid influencing the performance of the
hotpath.

(Multi-threaded processes typically implicitly use FUT_OFF_MMSHARED by
setting clear_child_tid such that it points into anonymous memory, which
causes mm_release() in a multi-threaded mm to perform FUTEX_WAKE.)

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_