# CVE-2026-23346: arm64: io: Extract user memory type in ioremap_prot()

> A flaw in the Linux kernel arm64 ioremap_prot function causes kernel faults when accessing user memory mappings, leading to a denial of service.

- **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:** 25 Mar 2026
- **Updated:** 19 Jun 2026
- **Also known as:** AZL-80627, BELL-CVE-2026-23346, DEBIAN-CVE-2026-23346, GHSA-xqp7-9gqv-6978, ROOT-OS-DEBIAN-12-CVE-2026-23346, ROOT-OS-DEBIAN-13-CVE-2026-23346, ROOT-OS-UBUNTU-2404-CVE-2026-23346, UBUNTU-CVE-2026-23346

## What is CVE-2026-23346?

CVE-2026-23346 is a medium-severity denial of service vulnerability in Linux kernel, published on 25 Mar 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: io: Extract user memory type in ioremap_prot()

The only caller of ioremap_prot() outside of the generic ioremap()
implementation is generic_access_phys(), which passes a 'pgprot_t' value
determined from the user mapping of the target 'pfn' being accessed by
the kernel. On arm64, the 'pgprot_t' contains all of the non-address
bits from the pte, including the permission controls, and so we end up
returning a new user mapping from ioremap_prot() which faults when
accessed from the kernel on systems with PAN:

  | Unable to handle kernel read from unreadable memory at virtual address ffff80008ea89000
  | ...
  | Call trace:
  |   __memcpy_fromio+0x80/0xf8
  |   generic_access_phys+0x20c/0x2b8
  |   __access_remote_vm+0x46c/0x5b8
  |   access_remote_vm+0x18/0x30
  |   environ_read+0x238/0x3e8
  |   vfs_read+0xe4/0x2b0
  |   ksys_read+0xcc/0x178
  |   __arm64_sys_read+0x4c/0x68

Extract only the memory type from the user 'pgprot_t' in ioremap_prot()
and assert that we're being passed a user mapping, to protect us against
any changes in future that may require additional handling. To avoid
falsely flagging users of ioremap(), provide our own ioremap() macro
which simply wraps __ioremap_prot().

## Which versions are affected by CVE-2026-23346?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23346?

Apply the vendor's patch.

## Is CVE-2026-23346 being exploited?

There is no known exploitation of CVE-2026-23346 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-2026-23346 and fix it if it is affected.

What it is: CVE-2026-23346 is a medium-severity denial of service vulnerability in Linux kernel, published on 25 Mar 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-2026-23346 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-2026-23346/ (Markdown: https://insights.sbomify.com/CVE-2026-23346/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23346
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23346
- OSV: https://osv.dev/vulnerability/CVE-2026-23346

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23346/
Summaries are generated and may contain mistakes; the official description above is the record.