GitHub Advisoryadvisory · crates.io
GHSA-pmf6-rcx4-v53v mkfifo: permissions of an existing file are changed after FIFO creation fails
HIGH
Official page ↗
- Aliases
- CVE-2026-35341
- Ecosystem
- crates.io
- Packages
- uu_mkfifo
- Severity
- High
- CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- Weaknesses
- CWE-281, CWE-732
- Reviewed
- 2026-07-06
Affected packages
• crates.io uu_mkfifo: < 0.6.0 → fixed in 0.6.0
Description
When `mkfifo()` fails (e.g. target already exists), the code shows an error but is missing a `continue;`, so it falls through to `fs::set_permissions` and changes the permissions of the pre-existing file to the default FIFO mode (`0o666` & umask -> `0644`).
```
$ touch secret; chmod 000 secret
$ coreutils mkfifo secret fifo3 fifo4
mkfifo: cannot create fifo 'secret': File exists
$ ll secret # uutils:
prw-r--r-- secret # changed to 644 (GNU leaves it 000)
```
Impact: an attacker (or user error) can relax permissions on sensitive owner-only files such as SSH private keys, exposing them to other users. Recommendation: add `continue;` after the error.
Remediation: Acknowledged by Canonical; fixed in PR #10376.
---
_Reported by Zellic in the *uutils coreutils Program Security Assessment* (prepared for Canonical, Jan 20 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`. Finding 3.8. Credit: Zellic._
_Upstream tracking issue: https://github.com/uutils/coreutils/issues/10020 · CVE-2026-35341_
Related
Alias · CVE (1)
- CVE-2026-35341 A vulnerability in uutils coreutils mkfifo allows for the unauthorized modification of permissions on existing files. vulnerability