# CVE-2026-23114: arm64/fpsimd: ptrace: Fix SVE writes on !SME systems

> A kernel bug causes a warning and potential instability when ptrace writes SVE registers on systems without SME support.

- **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:** 14 Feb 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2026-23114, DEBIAN-CVE-2026-23114, GHSA-g579-pq4g-x964, UBUNTU-CVE-2026-23114

## What is CVE-2026-23114?

CVE-2026-23114 is a medium-severity vulnerability in Linux kernel, published on 14 Feb 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:

arm64/fpsimd: ptrace: Fix SVE writes on !SME systems

When SVE is supported but SME is not supported, a ptrace write to the
NT_ARM_SVE regset can place the tracee into an invalid state where
(non-streaming) SVE register data is stored in FP_STATE_SVE format but
TIF_SVE is clear. This can result in a later warning from
fpsimd_restore_current_state(), e.g.

  WARNING: CPU: 0 PID: 7214 at arch/arm64/kernel/fpsimd.c:383 fpsimd_restore_current_state+0x50c/0x748

When this happens, fpsimd_restore_current_state() will set TIF_SVE,
placing the task into the correct state. This occurs before any other
check of TIF_SVE can possibly occur, as other checks of TIF_SVE only
happen while the FPSIMD/SVE/SME state is live. Thus, aside from the
warning, there is no functional issue.

This bug was introduced during rework to error handling in commit:

  9f8bf718f2923 ("arm64/fpsimd: ptrace: Gracefully handle errors")

... where the setting of TIF_SVE was moved into a block which is only
executed when system_supports_sme() is true.

Fix this by removing the system_supports_sme() check. This ensures that
TIF_SVE is set for (SVE-formatted) writes to NT_ARM_SVE, at the cost of
unconditionally manipulating the tracee's saved svcr value. The
manipulation of svcr is benign and inexpensive, and we already do
similar elsewhere (e.g. during signal handling), so I don't think it's
worth guarding this with system_supports_sme() checks.

Aside from the above, there is no functional change. The 'type' argument
to sve_set_common() is only set to ARM64_VEC_SME (in ssve_set())) when
system_supports_sme(), so the ARM64_VEC_SME case in the switch statement
is still unreachable when !system_supports_sme(). When
CONFIG_ARM64_SME=n, the only caller of sve_set_common() is sve_set(),
and the compiler can constant-fold for the case where type is
ARM64_VEC_SVE, removing the logic for other cases.

## Which versions are affected by CVE-2026-23114?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23114?

Apply the vendor's patch.

## Is CVE-2026-23114 being exploited?

There is no known exploitation of CVE-2026-23114 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-2026-23114 and fix it if it is affected.

What it is: CVE-2026-23114 is a medium-severity vulnerability in Linux kernel, published on 14 Feb 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-2026-23114 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-2026-23114/ (Markdown: https://insights.sbomify.com/CVE-2026-23114/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23114
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23114
- OSV: https://osv.dev/vulnerability/CVE-2026-23114

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23114/
Summaries are generated and may contain mistakes; the official description above is the record.