# CVE-2026-98373: mm/hugetlb: preserve mremap address delta when skipping page tables

> A local attacker can trigger a kernel panic in the Linux kernel's hugetlb subsystem via mremap, causing a denial of service.

- **Severity:** Not scored
- **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:** 7 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-106730, BELL-CVE-2026-98373, DEBIAN-CVE-2026-98373, GHSA-7phr-r52q-xg92, UBUNTU-CVE-2026-98373

## What is CVE-2026-98373?

CVE-2026-98373 is a memory corruption vulnerability in Linux, published on 7 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:

mm/hugetlb: preserve mremap address delta when skipping page tables

move_hugetlb_page_tables() optimizes mremap() by advancing to the last
entry in the page table when the source page table does not exist, either
initially or after unsharing a PMD table.  The common loop increment then
steps to the first entry in the next page table.

However, the code advances both the source and destination addresses to
the last entries in their respective page tables, which is wrong.  The
destination address must be advanced only by the same amount as the source
address.

If the source and destination offsets within their page tables differ, the
destination address can be advanced too far, causing follow-up issues. 
Fix this by advancing the destination address by the source advance
distance.

With a reproducer, we were able to trigger a kernel panic on x86-64.  With
this fix in place, we can no longer reproduce the issue.

## Which versions are affected by CVE-2026-98373?


## How do I fix CVE-2026-98373?

Apply the vendor's patch.

## Is CVE-2026-98373 being exploited?

There is no known exploitation of CVE-2026-98373 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98373 and fix it if it is affected.

What it is: CVE-2026-98373 is a memory corruption vulnerability in Linux, published on 7 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-2026-98373 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-2026-98373/ (Markdown: https://insights.sbomify.com/CVE-2026-98373/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98373
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98373
- OSV: https://osv.dev/vulnerability/CVE-2026-98373

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98373/
Summaries are generated and may contain mistakes; the official description above is the record.