CVE-2022-40897 — Python Packaging Authority (PyPA) setuptools before 65

Python Packaging Authority (PyPA) setuptools before 65.5.1 allows remote attackers to cause a denial of service via HTML in a crafted package or custom PackageIndex page. There is a Regular Expression Denial of Service (ReDoS) in package_index.py.

01What is this vulnerability?

Python Packaging Authority (PyPA) setuptools before 65.5.1 allows remote attackers to cause a denial of service via HTML in a crafted package or custom PackageIndex page. There is a Regular Expression Denial of Service (ReDoS) in package_index.py.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2022-12-22T00:00:00.000Z
• Last modified: 2025-11-04T16:09:54.794Z

09References

• github.com — https://github.com/pypa/setuptools/blob/fe8a98e696241487ba6ac9f91faa38ade939ec5d…
• pyup.io — https://pyup.io/posts/pyup-discovers-redos-vulnerabilities-in-top-python-package…
• github.com — https://github.com/pypa/setuptools/commit/43a9c9bfa6aa626ec2a22540bea28d2ca77964…
• pyup.io — https://pyup.io/vulnerabilities/CVE-2022-40897/52495/
• github.com — https://github.com/pypa/setuptools/compare/v65.5.0...v65.5.1
• security.netapp.com — https://security.netapp.com/advisory/ntap-20230214-0001/
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
• security.netapp.com — https://security.netapp.com/advisory/ntap-20240621-0006/