# CVE-2026-35373: uutils coreutils ln Local Denial of Service via Improper Handling of Non-UTF-8 Filenames

> The uutils coreutils ln utility fails to create links for non-UTF-8 filenames, causing local denial of service in automated scripts.

- **Severity:** Low 3.3 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L`)
- **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:** 22 Apr 2026
- **Updated:** 22 Apr 2026
- **Also known as:** DEBIAN-CVE-2026-35373, GHSA-jcjr-rh8q-7xqf, UBUNTU-CVE-2026-35373

## What is CVE-2026-35373?

CVE-2026-35373 is a low-severity denial of service vulnerability in Uutils coreutils, published on 22 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A logic error in the ln utility of uutils coreutils causes the program to reject source paths containing non-UTF-8 filename bytes when using target-directory forms (e.g., ln SOURCE... DIRECTORY). While GNU ln treats filenames as raw bytes and creates the links correctly, the uutils implementation enforces UTF-8 encoding, resulting in a failure to stat the file and a non-zero exit code. In environments where automated scripts or system tasks process valid but non-UTF-8 filenames common on Unix filesystems, this divergence causes the utility to fail, leading to a local denial of service for those specific operations.

Weakness: CWE-176 (Improper Handling of Unicode Encoding)

## Which versions are affected by CVE-2026-35373?

2 open source packages ship an affected version, including uu_ln. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `uu_ln` | crates.io | All versions | 0.6.0 |
| `uu_ln` | crates.io | All versions | 0.6.0 |

Products: Uutils Coreutils.

## How do I fix CVE-2026-35373?

Upgrade uu_ln to 0.6.0 or later.

## Is CVE-2026-35373 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35373 exists.

## Other vulnerabilities in Uutils coreutils

- [CVE-2026-35338](https://insights.sbomify.com/CVE-2026-35338/): uutils coreutils chmod Path Traversal Bypass of --preserve-root (high 7.3)
- [CVE-2026-35368](https://insights.sbomify.com/CVE-2026-35368/): uutils coreutils chroot Local Privilege Escalation and chroot Escape in via Name Service Switch (NSS) Injection (high 7.2)
- [CVE-2026-35341](https://insights.sbomify.com/CVE-2026-35341/): uutils coreutils mkfifo Unauthorized Permission Change on Existing Files (high 7.1)
- [CVE-2026-35352](https://insights.sbomify.com/CVE-2026-35352/): uutils coreutils mkfifo Privilege Escalation via TOCTOU Race Condition (high 7.0)
- [CVE-2026-35349](https://insights.sbomify.com/CVE-2026-35349/): uutils coreutils Path-Based Safety Bypass with --preserve-root (medium 6.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-35373 and fix it if it is affected.

What it is: CVE-2026-35373 is a low-severity denial of service vulnerability in Uutils coreutils, published on 22 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35373 exists.

Affected packages and fixed versions:
- uu_ln (crates.io): affected all versions; fixed in 0.6.0
- uu_ln (crates.io): affected all versions; fixed in 0.6.0

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-2026-35373/ (Markdown: https://insights.sbomify.com/CVE-2026-35373/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-35373
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-35373
- OSV: https://osv.dev/vulnerability/CVE-2026-35373

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-35373/
Summaries are generated and may contain mistakes; the official description above is the record.