CVE-2026-35358 is a medium-severity (CVSS 4.4) CWE-706 vulnerability in uu_cp. O3 Security confirms whether CVE-2026-35358 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
uutils coreutils cp Semantic Loss and Potential Denial of Service with -R via Device Node Stream Reading
Real-World Exposure
uu_cpReal-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
The cp utility in uutils coreutils, when performing recursive copies (-R), incorrectly treats character and block device nodes as stream sources rather than preserving them. Because the implementation reads bytes into regular files at the destination instead of using mknod, device semantics are destroyed (e.g., /dev/null becomes a regular file). This behavior can lead to runtime denial of service through disk exhaustion or process hangs when reading from unbounded device nodes.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | uu_cp | all versions | 0.7.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uu_cp. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update uu_cp to 0.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-35358 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.
How O3 protects you
O3 pinpoints whether CVE-2026-35358 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-35358. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-35358 in your dependencies?
O3 detects CVE-2026-35358 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.