CVE-2026-35373 is a low-severity (CVSS 3.3) CWE-176 vulnerability in uu_ln. A fix is available for uu_ln — see the affected versions and patch details below.
ln: rejects non-UTF-8 source filenames in target-directory mode
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-35373.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-35373 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 382,621 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
uu_lnReal-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
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | uu_ln | all versions | 0.6.0cargo update -p uu_ln --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_ln, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update uu_ln to 0.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-35373 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-2026-35373 in your dependencies?
Find it across crates.io, including transitive dependencies.