GHSA-2w8r-9xj7-69j5
LOWGHSA-2w8r-9xj7-69j5 is a low-severity (CVSS 3.3) CWE-377 vulnerability in uu_mktemp. O3 Security confirms whether GHSA-2w8r-9xj7-69j5 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
mktemp: empty TMPDIR creates temp files in CWD instead of /tmp
Blast Radius
uu_mktempReal-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 mktemp utility in uutils coreutils fails to properly handle an empty TMPDIR environment variable. Unlike GNU mktemp, which falls back to /tmp when TMPDIR is an empty string, the uutils implementation treats the empty string as a valid path. This causes temporary files to be created in the current working directory (CWD) instead of the intended secure temporary directory. If the CWD is more permissive or accessible to other users than /tmp, it may lead to unintended information disclosure or unauthorized access to temporary data.
Zellic finding 3.11. 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_mktemp | all versions | 0.6.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uu_mktemp. 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_mktemp to 0.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-2w8r-9xj7-69j5 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-2w8r-9xj7-69j5 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-2w8r-9xj7-69j5. 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-2w8r-9xj7-69j5 in your dependencies?
O3 detects GHSA-2w8r-9xj7-69j5 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.