GHSA-2w8r-9xj7-69j5 is a low-severity (CVSS 3.3) CWE-377 vulnerability in uu_mktemp. A fix is available for uu_mktemp — see the affected versions and patch details below.
mktemp: empty TMPDIR creates temp files in CWD instead of /tmp
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-2w8r-9xj7-69j5.
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
GHSA-2w8r-9xj7-69j5 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 376,715 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
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 | 0.6.0cargo update -p uu_mktemp --precise 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-2w8r-9xj7-69j5 can be triaged on real exposure rather than presence alone.
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 Security finds GHSA-2w8r-9xj7-69j5 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.