# CVE-2026-72200: ntfs: detect mapping-pairs LCN accumulator overflow

> A signed integer overflow in the Linux kernel NTFS parser allows attackers to corrupt runlists, potentially leading to unauthorized memory access or code execution.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-96534, BELL-CVE-2026-72200, DEBIAN-CVE-2026-72200, GHSA-j9wr-x478-q66c, UBUNTU-CVE-2026-72200

## What is CVE-2026-72200?

CVE-2026-72200 is a critical vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ntfs: detect mapping-pairs LCN accumulator overflow

The NTFS mapping-pairs parser accumulates relative LCN deltas in a
signed integer.  A corrupted attribute can drive that addition past
the representable range.

One corrupt runlist shape sets the accumulated LCN to S64_MAX and
then adds a delta of 1 in the next mapping-pairs entry.

Signed overflow is undefined and can turn an invalid runlist into a
different set of physical clusters.

Check the LCN addition for overflow before storing the next run.

## Which versions are affected by CVE-2026-72200?


## How do I fix CVE-2026-72200?

Apply the vendor's patch.

## Is CVE-2026-72200 being exploited?

There is no known exploitation of CVE-2026-72200 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72200 and fix it if it is affected.

What it is: CVE-2026-72200 is a critical vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-72200 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-2026-72200/ (Markdown: https://insights.sbomify.com/CVE-2026-72200/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72200
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72200
- OSV: https://osv.dev/vulnerability/CVE-2026-72200

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72200/
Summaries are generated and may contain mistakes; the official description above is the record.