CVE-2026-35378 is a low-severity (CVSS 3.3) CWE-768 vulnerability in coreutils. O3 Security confirms whether CVE-2026-35378 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
uutils coreutils expr Local Denial of Service via Eager Evaluation of Parenthesized Subexpressions
Real-World Exposure
coreutilsReal-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 expr utility of uutils coreutils causes the program to evaluate parenthesized subexpressions during the parsing phase rather than at the execution phase. This implementation flaw prevents the utility from performing proper short-circuiting for logical OR (|) and AND (&) operations. As a result, arithmetic errors (such as division by zero) occurring within "dead" branches, branches that should be ignored due to short-circuiting, are raised as fatal errors. This divergence from GNU expr behavior can cause guarded expressions within shell scripts to fail with hard errors instead of returning expected boolean results, leading to premature script termination and breaking GNU-compatible shell control flow.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | coreutils | all versions | 0.8.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for coreutils. 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 coreutils to 0.8.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-35378 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-2026-35378 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-2026-35378. 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-2026-35378 in your dependencies?
O3 detects CVE-2026-35378 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.