CVE-2026-35341 is a high-severity (CVSS 7.1) CWE-732 vulnerability in uu_mkfifo. A fix is available for uu_mkfifo — see the affected versions and patch details below.
mkfifo: permissions of an existing file are changed after FIFO creation fails
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-35341.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
uu_mkfifoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
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
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | uu_mkfifo | all versions | 0.6.0cargo update -p uu_mkfifo --precise 0.6.0 |
Affected Products
coreutilsuutilsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uu_mkfifo, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update uu_mkfifo to 0.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-35341 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-35341 in your dependencies?
Find it across crates.io, including transitive dependencies.