# CVE-2026-99228: Linux kernel io_uring signal loss in worker exit

Source: https://junglewise.ai/threats/cve-2026-99228-in-the-linux-kernel-the-following-vulnerability-has-been-resolved  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-02. Updated: 2026-11-02  
License: CC BY 4.0 with a link back

CVE-2026-99228 · Severity: info · Published 2026-11-02

The Linux kernel's io_uring subsystem can lose a signal meant to wake worker threads during shutdown, causing the process to hang indefinitely. This affects applications using io_uring for asynchronous I/O operations, particularly when opening special files like FIFOs. A hanging process may require forced termination by system administrators.

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

## Quick answers

**Is CVE-2026-99228 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-99228 being exploited in the wild.

**How severe is CVE-2026-99228?** Informational severity, published 2 November 2026.

**Which products and versions are affected?** Linux Kernel affected versions not specified in advisory.

**Is there a fix for CVE-2026-99228?** 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-2026-99228 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-99228?** 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

In io_uring's io-wq worker thread exit path, the signal TIF_NOTIFY_SIGNAL is set once to wake all workers from interruptible sleep, but if a worker hasn't yet started bounded work when the signal is cleared, it will miss the signal and hang in the wait path. The vulnerability occurs due to a race condition between io_wq_exit_workers() signaling and io_worker_handle_work() clearing the flag. The fix ensures TIF_NOTIFY_SIGNAL is set for bounded work that starts while IO_WQ_BIT_EXIT is set, with a memory barrier preventing the race.

## Affected products

- Linux kernel affected versions not specified in advisory

## Timeline

- 2026-11-02: disclosed

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