CVE-2026-35379 is a low-severity (CVSS 3.3) CWE-684 vulnerability in coreutils. A fix is available for coreutils — see the affected versions and patch details below.
uutils coreutils tr Local Logic Error and Data Integrity Issue in Character Class Handling
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-2026-35379.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-35379 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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 tr utility of uutils coreutils causes the program to incorrectly define the [:graph:] and [:print:] character classes. The implementation mistakenly includes the ASCII space character (0x20) in the [:graph:] class and excludes it from the [:print:] class, effectively reversing the standard behavior established by POSIX and GNU coreutils. This vulnerability leads to unintended data modification or loss when the utility is used in automated scripts or data-cleaning pipelines that rely on standard character class semantics. For example, a command executed to delete all graphical characters while intending to preserve whitespace will incorrectly delete all ASCII spaces, potentially resulting in data corruption or logic failures in downstream processing.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | coreutils | all versions | 0.8.0cargo update -p coreutils --precise 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, 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-2026-35379 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-35379 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-35379. 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-2026-35379 in your dependencies?
O3 Security finds CVE-2026-35379 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.