# CVE-2026-64106: KVM: arm64: vgic-its: Reject restored DTE with out-of-range num_eventid_bits

> A flaw in the Linux kernel's KVM arm64 vgic-its allows a local attacker to cause a denial of service by restoring a device table entry with invalid event ID bits.

- **Severity:** Critical 9.0 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-64106, DEBIAN-CVE-2026-64106, GHSA-gf7v-gpf5-6fgc, ROOT-OS-DEBIAN-11-CVE-2026-64106, ROOT-OS-UBUNTU-2204-CVE-2026-64106, UBUNTU-CVE-2026-64106

## What is CVE-2026-64106?

CVE-2026-64106 is a critical denial of service vulnerability in Linux kernel, published on 19 Jul 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:

KVM: arm64: vgic-its: Reject restored DTE with out-of-range num_eventid_bits

Userspace can restore an ITS Device Table Entry whose Size field encodes
more EventID bits than the virtual ITS supports.  The live MAPD path
rejects that state, but vgic_its_restore_dte() accepts it and stores the
out-of-range value in dev->num_eventid_bits.

Reject restored DTEs with num_eventid_bits > VITS_TYPER_IDBITS before
allocating the device.  This mirrors the MAPD check and prevents the
restored state from reaching vgic_its_restore_itt(), where the unchecked
value can be converted into an oversized scan_its_table() range.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-64106?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64106?

Apply the vendor's patch.

## Is CVE-2026-64106 being exploited?

There is no known exploitation of CVE-2026-64106 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-2026-64106 and fix it if it is affected.

What it is: CVE-2026-64106 is a critical denial of service vulnerability in Linux kernel, published on 19 Jul 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-2026-64106 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-2026-64106/ (Markdown: https://insights.sbomify.com/CVE-2026-64106/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64106
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64106
- OSV: https://osv.dev/vulnerability/CVE-2026-64106

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64106/
Summaries are generated and may contain mistakes; the official description above is the record.