GHSA-pmfc-4wjj-gmhx is a low-severity (CVSS 3.3) CWE-684 vulnerability in uu_cut. O3 Security confirms whether GHSA-pmfc-4wjj-gmhx is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
cut: -s ignored in -z -d '' newline-delimiter mode
Real-World Exposure
uu_cutReal-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
cut routes -z -d '' through a special newline-delimiter path that ignores the -s only-delimited flag, emitting whole undelimited records (plus NUL) that should be suppressed. Pipelines relying on cut -s to drop undelimited records process data that should be filtered.
printf 'abc' | cut -z -d '' -s -f 1 | od -An -tx1 # GNU: no output ; uutils: 61 62 63 00
Zellic private finding (zellic-ext/coreutils-private PR #102). Reported in the Zellic uutils coreutils Program Security Assessment (for Canonical, Jan 2026), audited commit 3a07ffc5a9bd4c283e75afa548ba1f1957bad242.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | uu_cut | 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_cut. 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_cut to 0.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pmfc-4wjj-gmhx 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 GHSA-pmfc-4wjj-gmhx 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 GHSA-pmfc-4wjj-gmhx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-pmfc-4wjj-gmhx in your dependencies?
O3 detects GHSA-pmfc-4wjj-gmhx 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.