# CVE-2026-90134: ntfs: fix kmap_local_page() usage in compress

> A memory corruption flaw in the Linux kernel NTFS driver allows local attackers to cause denial of service or execute arbitrary code via improper page mapping.

- **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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-90134, GHSA-8xqc-mr32-5fw8, UBUNTU-CVE-2026-90134

## What is CVE-2026-90134?

CVE-2026-90134 is a memory corruption vulnerability in Linux, published on 17 Sep 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:

ntfs: fix kmap_local_page() usage in compress

Several compressed I/O paths discard the address returned by
kmap_local_page() and later access or unmap the page using page_address().
This is invalid for highmem pages, and local mappings must also be unmapped
using the address returned by kmap_local_page().

Map each destination page in ntfs_decompress() only while producing the
current sub-block. Use memcpy_from_page(), memcpy_to_page(), and
memzero_page() for the other page accesses. Remove unnecessary local
mappings from ntfs_write_cb(), where pages are accessed through the vmap()
mapping.

## Which versions are affected by CVE-2026-90134?


## How do I fix CVE-2026-90134?

Apply the vendor's patch.

## Is CVE-2026-90134 being exploited?

There is no known exploitation of CVE-2026-90134 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90134 and fix it if it is affected.

What it is: CVE-2026-90134 is a memory corruption vulnerability in Linux, published on 17 Sep 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-2026-90134 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-2026-90134/ (Markdown: https://insights.sbomify.com/CVE-2026-90134/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90134
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90134
- OSV: https://osv.dev/vulnerability/CVE-2026-90134

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90134/
Summaries are generated and may contain mistakes; the official description above is the record.