# CVE-2026-35357: uutils coreutils cp Information Disclosure via Permission Handling Race

> A local attacker can exploit a race condition in the cp utility to read sensitive file contents before permissions are restricted.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **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-2026-35357, GHSA-2m8x-mvfx-gwgj, UBUNTU-CVE-2026-35357

## What is CVE-2026-35357?

CVE-2026-35357 is a medium-severity 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

The cp utility in uutils coreutils is vulnerable to an information disclosure race condition. Destination files are initially created with umask-derived permissions (e.g., 0644) before being restricted to their final mode (e.g., 0600) later in the process. A local attacker can race to open the file during this window; once obtained, the file descriptor remains valid and readable even after the permissions are tightened, exposing sensitive or private file contents.

Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition)

## Which versions are affected by CVE-2026-35357?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `coreutils` | crates.io | All versions to 0.8.0 | None |
| `coreutils` | crates.io | All versions to 0.8.0 | None |

Products: Uutils Coreutils.

## How do I fix CVE-2026-35357?

Apply the vendor's patch.

## Is CVE-2026-35357 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35357 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-2026-35357 and fix it if it is affected.

What it is: CVE-2026-35357 is a medium-severity 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-2026-35357 exists.

Affected packages and fixed versions:
- coreutils (crates.io): affected all versions up to 0.8.0; no fix listed
- coreutils (crates.io): affected all versions up to 0.8.0; no fix listed

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-2026-35357/ (Markdown: https://insights.sbomify.com/CVE-2026-35357/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-35357
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-35357
- OSV: https://osv.dev/vulnerability/CVE-2026-35357

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-35357/
Summaries are generated and may contain mistakes; the official description above is the record.