CVE-2021-44686

    Dashboard / Vulnerabilities / CVE-2021-44686

    CVE-2021-44686

    Published: 7 Dec 2021Last Modified: 7 Aug 2026

    Summary:

    Details: calibre before 5.32.0 contains a regular expression that is vulnerable to ReDoS (Regular Expression Denial of Service) in html_preprocess_rules in ebooks/conversion/preprocess.py.

    References: https://lists.debian.org/debian-lts-announce/2024/09/msg00005.html, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/W7QKFPYJ23KG6WJ5NIYAM4N2NWZCLQGL/, https://bugs.launchpad.net/calibre/+bug/1951979, https://github.com/dwisiswant0/advisory/issues/18, https://github.com/kovidgoyal/calibre/compare/v5.31.1...v5.32.0

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -f3ef3c85dd230b32d6955050111285ed82f04fef

    Affected versions

    v5.31.1
    v5.31.0

    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-2021-44686 | CVE-DB