# CVE-2026-98867: dm-pcache: bound the logical key offset from persistent memory

> A missing bounds check in the Linux kernel dm-pcache driver allows out-of-bounds writes via crafted persistent memory keys, potentially leading to code execution or system crashes.

- **Severity:** Not scored
- **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:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-98867, DEBIAN-CVE-2026-98867, GHSA-f472-jf6w-c35h, UBUNTU-CVE-2026-98867

## What is CVE-2026-98867?

CVE-2026-98867 is a memory corruption vulnerability in Linux, published on 18 Oct 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:

dm-pcache: bound the logical key offset from persistent memory

cache_key_decode() takes a key's logical off from the cache device and
later indexes req_key_tree->subtrees[] by it in get_subtree(). An off
past the device forms a subtree pointer outside the array, which
rb_insert() writes through during replay.

Reject a key of zero length, or whose off+len (computed in 64 bits)
exceeds the device size, before it is used.

## Which versions are affected by CVE-2026-98867?


## How do I fix CVE-2026-98867?

Apply the vendor's patch.

## Is CVE-2026-98867 being exploited?

There is no known exploitation of CVE-2026-98867 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98867 and fix it if it is affected.

What it is: CVE-2026-98867 is a memory corruption vulnerability in Linux, published on 18 Oct 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-2026-98867 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-2026-98867/ (Markdown: https://insights.sbomify.com/CVE-2026-98867/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98867
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98867
- OSV: https://osv.dev/vulnerability/CVE-2026-98867

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98867/
Summaries are generated and may contain mistakes; the official description above is the record.