PYSEC-2021-108

    Dashboard / Vulnerabilities / PYSEC-2021-108

    PYSEC-2021-108

    Published: 29 Jun 2021Last Modified: 8 Jun 2026

    Summary:

    Details: 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 parameter or redirected to via an HTTP redirect.

    References: https://github.com/advisories/GHSA-q2q7-5pp4-w6pg, https://github.com/urllib3/urllib3/commit/2d4a3fee6de2fa45eb82169361918f759269b4ec

    Affected packages

    Package

    Name: urllib3

    Purl: pkg:pypi/urllib3

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -2d4a3fee6de2fa45eb82169361918f759269b4ec

    Affected versions

    1.25.10
    1.25.11
    1.25.4
    1.25.5
    1.25.6
    1.25.7
    1.25.8
    1.25.9
    1.25.3
    1.25.2
    1.25.1
    1.25

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    PYSEC-2021-108 | CVE-DB