# CVE-2026-46257: Null dereference in Linux

> An attacker with local access can cause a kernel crash on ARM32 platforms by triggering a null pointer dereference in the SP804 timer driver when sched_clock is disabled.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 3 Jun 2026
- **Updated:** 3 Jun 2026
- **Also known as:** GHSA-w9qv-v668-q8rf, UBUNTU-CVE-2026-46257

## What is CVE-2026-46257?

CVE-2026-46257 is a medium-severity vulnerability in Linux kernel, published on 3 Jun 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:

clocksource/drivers/timer-sp804: Fix an Oops when read_current_timer is called on ARM32 platforms where the SP804 is not registered as the sched_clock.

On SP804, the delay timer shares the same clkevt instance with
sched_clock. On some platforms, when
sp804_clocksource_and_sched_clock_init is called with use_sched_clock
not set to 1, sched_clkevt is not properly initialized. However,
sp804_register_delay_timer is invoked unconditionally, and
read_current_timer() subsequently calls sp804_read on an uninitialized
sched_clkevt, leading to a kernel Oops when accessing
sched_clkevt->value.

Declare a dedicated clkevt instance exclusively for delay timer,
instead of sharing the same clkevt with sched_clock.  This ensures
that read_current_timer continues to work correctly regardless of
whether SP804 is selected as the sched_clock.

Weakness: CWE-908 (Use of Uninitialized Resource)

## Which versions are affected by CVE-2026-46257?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46257?

Apply the vendor's patch.

## Is CVE-2026-46257 being exploited?

There is no known exploitation of CVE-2026-46257 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-2026-46257 and fix it if it is affected.

What it is: CVE-2026-46257 is a medium-severity vulnerability in Linux kernel, published on 3 Jun 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-2026-46257 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-2026-46257/ (Markdown: https://insights.sbomify.com/CVE-2026-46257/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46257
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46257
- OSV: https://osv.dev/vulnerability/CVE-2026-46257

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46257/
Summaries are generated and may contain mistakes; the official description above is the record.