# CVE-2026-46065: fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info

> A use-after-free in the Linux kernel's fbdev deferred I/O allows attackers to cause a denial of service or potentially execute code via device hot-unplug.

- **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
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 May 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-88514, BELL-CVE-2026-46065, DEBIAN-CVE-2026-46065, GHSA-w279-mj9j-w893, ROOT-OS-DEBIAN-11-CVE-2026-46065, ROOT-OS-DEBIAN-12-CVE-2026-46065, ROOT-OS-UBUNTU-2204-CVE-2026-46065, ROOT-OS-UBUNTU-2404-CVE-2026-46065, UBUNTU-CVE-2026-46065

## What is CVE-2026-46065?

CVE-2026-46065 is a high-severity use after free vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info

Hold state of deferred I/O in struct fb_deferred_io_state. Allocate an
instance as part of initializing deferred I/O and remove it only after
the final mapping has been closed. If the fb_info and the contained
deferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info
to invalidate the mapping. Any access will then result in a SIGBUS
signal.

Fixes a long-standing problem, where a device hot-unplug happens while
user space still has an active mapping of the graphics memory. The hot-
unplug frees the instance of struct fb_info. Accessing the memory will
operate on undefined state.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime), CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-46065?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46065?

Apply the vendor's patch.

## Is CVE-2026-46065 being exploited?

There is no known exploitation of CVE-2026-46065 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46065 and fix it if it is affected.

What it is: CVE-2026-46065 is a high-severity use after free vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-46065 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-46065/ (Markdown: https://insights.sbomify.com/CVE-2026-46065/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46065
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46065
- OSV: https://osv.dev/vulnerability/CVE-2026-46065

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46065/
Summaries are generated and may contain mistakes; the official description above is the record.