# CVE-2026-46154: sched_ext: Read scx_root under scx_cgroup_ops_rwsem in cgroup setters

> A use-after-free in the Linux kernel scheduler allows attackers to execute arbitrary code or escalate privileges if sched_ext is enabled.

- **Severity:** High 7.0 (`CVSS:3.1/AV:L/AC:H/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-2026-46154, DEBIAN-CVE-2026-46154, GHSA-xcff-q6mv-v46w, UBUNTU-CVE-2026-46154

## What is CVE-2026-46154?

CVE-2026-46154 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:

sched_ext: Read scx_root under scx_cgroup_ops_rwsem in cgroup setters

scx_group_set_{weight,idle,bandwidth}() cache scx_root before acquiring
scx_cgroup_ops_rwsem, so the pointer can be stale by the time the op runs.
If the loaded scheduler is disabled and freed (via RCU work) and another is
enabled between the naked load and the rwsem acquire, the reader sees
scx_cgroup_enabled=true (the new scheduler's) but dereferences the freed one
- UAF on SCX_HAS_OP(sch, ...) / SCX_CALL_OP(sch, ...).

scx_cgroup_enabled is toggled only under scx_cgroup_ops_rwsem write
(scx_cgroup_{init,exit}), so reading scx_root inside the rwsem read section
correlates @sch with the enabled snapshot.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-46154?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46154?

Apply the vendor's patch.

## Is CVE-2026-46154 being exploited?

There is no known exploitation of CVE-2026-46154 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-2026-46154 and fix it if it is affected.

What it is: CVE-2026-46154 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: There is no known exploitation of CVE-2026-46154 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-2026-46154/ (Markdown: https://insights.sbomify.com/CVE-2026-46154/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46154
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46154
- OSV: https://osv.dev/vulnerability/CVE-2026-46154

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46154/
Summaries are generated and may contain mistakes; the official description above is the record.