# CVE-2026-72018: dibs: loopback: validate offset and size in move_data()

> An out-of-bounds write in the Linux kernel's dibs loopback driver allows attackers to corrupt memory, potentially leading to code execution or privilege escalation.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/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:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-72018, DEBIAN-CVE-2026-72018, GHSA-96mx-hwj9-j649, UBUNTU-CVE-2026-72018

## What is CVE-2026-72018?

CVE-2026-72018 is a high-severity memory corruption vulnerability in Linux, published on 15 Aug 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:

dibs: loopback: validate offset and size in move_data()

The loopback move_data() performs a memcpy into the registered DMB
without checking whether offset + size exceeds the DMB length.  Unlike
real ISM hardware, which enforces memory region bounds natively, the
software loopback has no such protection.

A peer-supplied out-of-bounds offset or oversized write would result in
an OOB write past the allocated kernel buffer.  Add an explicit bounds
check before the memcpy to reject such requests with -EINVAL.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-72018?


## How do I fix CVE-2026-72018?

Apply the vendor's patch.

## Is CVE-2026-72018 being exploited?

There is no known exploitation of CVE-2026-72018 in the wild and no public exploit code.

Public exploit code:

- CVE-2026-72018 (github_poc): https://github.com/0xredash/CVE-2026-72018

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72018 and fix it if it is affected.

What it is: CVE-2026-72018 is a high-severity memory corruption vulnerability in Linux, published on 15 Aug 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-2026-72018 in the wild and no public exploit code.

Affected product: Linux. 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-2026-72018/ (Markdown: https://insights.sbomify.com/CVE-2026-72018/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72018
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72018
- OSV: https://osv.dev/vulnerability/CVE-2026-72018

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72018/
Summaries are generated and may contain mistakes; the official description above is the record.