CVE-2026-34591 — poetry
Fix: python-poetry/poetry@ed59537CVE-2026-34591 is a Path Traversal vulnerability in poetry. A fix is available for poetry — see the affected versions and patch details below.
Poetry Has Wheel Path Traversal Which Can Lead to Arbitrary File Write
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-2026-34591.
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.
Real-World Exposure
poetryReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Poetry is a dependency manager for Python. From version 1.4.0 to before version 2.3.3, a crafted wheel can contain ../ paths that Poetry writes to disk without containment checks, allowing arbitrary file write with the privileges of the Poetry process. It is reachable from untrusted package artifacts during normal install flows. (Normally, installing a malicious wheel is not sufficient for execution of malicious code. Malicious code will only be executed after installation if the malicious package is imported or invoked by the user.). This issue has been patched in version 2.3.3.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | poetry | ≥ 1.4.0&&< 2.3.3 | 2.3.3pip install --upgrade 'poetry==2.3.3' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for poetry, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update poetry to 2.3.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34591 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-2026-34591 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-34591. 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-2026-34591 in your dependencies?
O3 Security finds CVE-2026-34591 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.