# CVE-2026-46215: drm: Set old handle to NULL before prime swap in change_handle

> A race condition in the Linux kernel DRM subsystem allows a use-after-free, potentially enabling local attackers to execute code or escalate privileges.

- **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:** 28 May 2026
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2026-46215, DEBIAN-CVE-2026-46215, GHSA-gm2j-59pp-6cxj, UBUNTU-CVE-2026-46215

## What is CVE-2026-46215?

CVE-2026-46215 is a high-severity use after free vulnerability in Linux kernel, published on 28 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:

drm: Set old handle to NULL before prime swap in change_handle

There was a potential race condition in change_handle. The ioctl
briefly had a single object with two idr entries; a concurrent
gem_close could delete the object and remove one of the handles
while leaving the other one dangling, which could subsequently
be dereferenced for a use-after-free.

To fix this, do the same dance that gem_close itself does.
(f6cd7daecff5 drm: Release driver references to handle before making it available again)
First idr_replace the old handle to NULL. Later, if the prime
operations are successful, actually close it.

create_tail required a similar dance to avoid a similar problem.
(bd46cece51a3 drm/gem: Fix race in drm_gem_handle_create_tail())
It idr_allocs the new handle with NULL, then swaps in the correct
object later to avoid races. We don't need to do that here, since
the only operations that could race are drm_prime, and
change_handle holds the prime lock for the entire duration.

v2: cleanups of error paths

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-46215?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46215?

Apply the vendor's patch.

## Is CVE-2026-46215 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-46215 exists.

Public exploit code:

- https://github.com/0xCyberstan/CVE-2026-46215-POC (github_poc): https://github.com/0xCyberstan/CVE-2026-46215-POC
- CVE-2026-46215 DRM GEM UAF Exploit for Linux 7.0 - The first working PoC for linux kernel 7 use after free- by Antonius (sw0rdm4n, w1sdom, ev1lut10n) (github_poc): https://github.com/bluedragonsecurity/CVE-2026-46215-exploit-linux-7.0-uaf-stable
- This is an exploit for CVE-2026-46215 (Linux Kernel Use After Free) Adapted for Linux 7.0 !!! by Antonius (ev1lut10n / sw0rdm4n) (github_poc): https://github.com/bluedragonsecurity/CVE-2026-46215-EXPLOIT

## 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-2026-46215 and fix it if it is affected.

What it is: CVE-2026-46215 is a high-severity use after free vulnerability in Linux kernel, published on 28 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-46215 exists.

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-2026-46215/ (Markdown: https://insights.sbomify.com/CVE-2026-46215/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46215
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46215
- OSV: https://osv.dev/vulnerability/CVE-2026-46215

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46215/
Summaries are generated and may contain mistakes; the official description above is the record.