CVE-2022-40897 is a medium-severity (CVSS 5.9) CWE-1333 vulnerability in setuptools. 1 public exploit reference exists, so weaponization risk is real. A fix is available for setuptools — see the affected versions and patch details below.
pypa/setuptools vulnerable to Regular Expression Denial of Service (ReDoS)
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 CVE-2022-40897.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2022-40897 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
setuptoolsReal-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
Python Packaging Authority (PyPA)'s setuptools is a library designed to facilitate packaging Python projects. Setuptools version 65.5.0 and earlier could allow remote attackers to cause a denial of service by fetching malicious HTML from a PyPI package or custom PackageIndex page due to a vulnerable Regular Expression in package_index. This has been patched in version 65.5.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | setuptools | all versions | 65.5.1pip install --upgrade 'setuptools==65.5.1' |
Affected Products
setuptoolspythonResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for setuptools, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update setuptools to 65.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-40897 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 8 | python39:3.9-8100020240214182535.7044f6c1 | RHSA-2024:2985 |
| Red Hat Enterprise Linux 8 | python27:2.7-8100020240208011952.5f0f67de | RHSA-2024:2987 |
| Red Hat Enterprise Linux 8 | python-setuptools-0:39.2.0-6.el8_7.1 | RHSA-2023:0835 |
| Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | python39:3.9-8060020240916062113.6a631399 | RHSA-2024:6915 |
| Red Hat Enterprise Linux 8.6 Extended Update Support | python-setuptools-0:39.2.0-7.el8_6 | RHSA-2023:7395 |
| Red Hat Enterprise Linux 8.8 Extended Update Support | python39:3.9-8080020240402104641.93c2fc2f | RHSA-2024:4421 |
| Red Hat Enterprise Linux 9 | python-setuptools-0:53.0.0-10.el9_1.1 | RHSA-2023:0952 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | rh-python38-python-setuptools-0:41.6.0-8.el7 | RHSA-2023:6793 |
Frequently Asked Questions
Is CVE-2022-40897 in your dependencies?
Find it across PyPI, including transitive dependencies.