# CVE-2026-72194: fs/ntfs3: add depth limit to indx_find_buffer to prevent stack overflow

> A crafted NTFS image causes unbounded recursion in the Linux kernel, leading to a stack overflow and system panic when mounting and deleting files.

- **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:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-72194, DEBIAN-CVE-2026-72194, GHSA-hqq4-5743-j5rq, UBUNTU-CVE-2026-72194

## What is CVE-2026-72194?

CVE-2026-72194 is a critical denial of service 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:

fs/ntfs3: add depth limit to indx_find_buffer to prevent stack overflow

indx_find_buffer() recursively descends the B+ tree index with no depth
limit.  A crafted NTFS image with circular index node references causes
unbounded recursion, overflowing the kernel stack and panicking the
system.

This is reachable by mounting a malicious NTFS filesystem (e.g. from a
USB drive via desktop automount) and deleting a file whose index entry
triggers the rebalancing fallback path in indx_delete_entry().

Add a depth parameter and bail out with -EINVAL when it reaches the
fnd->nodes array bound, matching the constraint already enforced by
fnd_push() in indx_find().

The related function indx_find() was previously patched for a similar
infinite-loop issue (commit 1732053c8a6b), but indx_find_buffer() was
missed.

## Which versions are affected by CVE-2026-72194?


## How do I fix CVE-2026-72194?

Apply the vendor's patch.

## Is CVE-2026-72194 being exploited?

There is no known exploitation of CVE-2026-72194 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72194 and fix it if it is affected.

What it is: CVE-2026-72194 is a critical denial of service 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-2026-72194 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-2026-72194/ (Markdown: https://insights.sbomify.com/CVE-2026-72194/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72194
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72194
- OSV: https://osv.dev/vulnerability/CVE-2026-72194

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72194/
Summaries are generated and may contain mistakes; the official description above is the record.