# CVE-2026-99050: gpio: mpsse: fix race when arming the IRQ poll worker


- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 24 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-99050, GHSA-77g9-3gmv-7p3q, UBUNTU-CVE-2026-99050

## What is CVE-2026-99050?

CVE-2026-99050 is a high-severity vulnerability in Linux, published on 23 Oct 2026. 

### Official description

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

gpio: mpsse: fix race when arming the IRQ poll worker

gpio_mpsse_irq_enable() arms the poll worker before publishing it:
schedule_work() runs before the worker is added to priv->workers. If
gpio_mpsse_disconnect() walks the list in that window it misses the
worker, and once disconnect returns, the USB core frees mpsse_priv
while the orphaned gpio_mpsse_poll() work keeps accessing it, causing
a use-after-free.

Fix this by publishing and arming the worker in one irq_spin
critical section. Teardown walks the same list under irq_spin, so a
worker found on the list is guaranteed to be armed, and
cancel_work_sync() handles it whether it is queued or running.

A worker armed after the disconnect walk would still be missed, so
also set a new priv->dying flag under irq_spin before the teardown
walk, and check it in the same critical section, freeing it via
kfree_rcu() instead when the device is going away, since kfree()
would be called with the IRQ core's raw spinlock held and may sleep
on PREEMPT_RT. schedule_work() is safe to call with irq_spin held,
and the next probe gets a fresh mpsse_priv, so the flag never needs
to be cleared.

This issue was found by an in-house static analysis tool.

## Which versions are affected by CVE-2026-99050?


## How do I fix CVE-2026-99050?

Upgrade to a fixed version.

## Is CVE-2026-99050 being exploited?

There is no known exploitation of CVE-2026-99050 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-99050 and fix it if it is affected.

What it is: CVE-2026-99050 is a high-severity vulnerability in Linux, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-99050 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-99050/ (Markdown: https://insights.sbomify.com/CVE-2026-99050/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-99050
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-99050
- OSV: https://osv.dev/vulnerability/CVE-2026-99050

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-99050/
Summaries are generated and may contain mistakes; the official description above is the record.