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OpenAdvisories
High USN-5812-1 1 CVE

python-urllib3 vulnerability

Published Jan 19, 2023 · Updated Feb 10, 2026

Ecosystem: Ubuntu

Summary

It was discovered that urllib3 incorrectly handled certain characters
in URLs. A remote attacker could possibly use this issue to cause urllib3
to consume resources, leading to a denial of service.

Fixed packages 1

ReleasePackageFixed in
Ubuntu · 20.04 LTS 20.04:LTS python-urllib3 1.25.8-2ubuntu0.2

Vulnerabilities 1

  • High 7.5
    CVE-2021-33503

    Catastrophic backtracking in URL authority parser when passed URL containing many @ characters

    An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a para…

    python-pip urllib3 python-urllib3 python-urllib3 Debian Ubuntu Azure Linux PyPI

References

  • report
    https://ubuntu.com/security/CVE-2021-33503