CVE-2021-3426

    Dashboard / Vulnerabilities / CVE-2021-3426

    CVE-2021-3426

    Published: 20 May 2021Last Modified: 7 Aug 2026

    Summary:

    Details: There's a flaw in Python 3's pydoc. A local or adjacent attacker who discovers or is able to convince another local or adjacent user to start a pydoc server could access the server and use it to disclose sensitive information belonging to the other user that they would not normally be able to access. The highest risk of this flaw is to data confidentiality. This flaw affects Python versions before 3.8.9, Python versions before 3.9.3 and Python versions before 3.10.0a7.

    References: https://lists.debian.org/debian-lts-announce/2023/06/msg00039.html, https://lists.debian.org/debian-lts-announce/2024/12/msg00000.html, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/25HVHLBGO2KNPXJ3G426QEYSSCECJDU5/, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BF2K7HEWADHN6P52R3QLIOX27U3DJ4HI/, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DQYPUKLLBOZMKFPO7RD7CENTXHUUEUV7/, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LM5V4VPLBHBEASSAROYPSHXGXGGPHNOE/, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/N6VXJZSZ6N64AILJX4CTMACYGQGHHD5C/, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QNGAFMPIYIVJ47FCF2NK2PIX22HUG35B/, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VPX7Y5GQDNB4FJTREWONGC4ZSVH7TGHF/, https://lists.debian.org/debian-lts-announce/2021/04/msg00005.html, https://security.gentoo.org/glsa/202104-04, https://security.netapp.com/advisory/ntap-20210629-0003/, https://bugzilla.redhat.com/show_bug.cgi?id=1935913, https://www.oracle.com/security-alerts/cpujan2022.html, https://www.oracle.com/security-alerts/cpuoct2021.html

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -8d21aa21f2cbc6d50aab3f420bb23be1d081dac4

    Affected versions

    v3.9.2
    v3.9.2rc1
    v3.9.0b5
    v3.9.0b3
    v3.9.0b1
    v3.9.0a2

    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
    CVE-2021-3426 | CVE-DB