CVE-2026-35378 is a low-severity (CVSS 3.3) CWE-768 vulnerability in coreutils. A fix is available for coreutils — see the affected versions and patch details below.
uutils coreutils expr Local Denial of Service via Eager Evaluation of Parenthesized Subexpressions
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-2026-35378.
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
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 | 0.8.0cargo update -p coreutils --precise 0.8.0 |
Affected Products
coreutilsuutilsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for coreutils, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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.
Frequently Asked Questions
Is CVE-2026-35378 in your dependencies?
Find it across crates.io, including transitive dependencies.