UBUNTU-CVE-2026-118694

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    UBUNTU-CVE-2026-118694

    Published: 28 Oct 2026Last Modified: 5 Nov 2026
    Upstream:
    CVE-2026-118694

    Summary:

    Details: python-markdown2 through 2.5.5 contains a denial of service vulnerability that allows remote users to exhaust CPU by submitting Markdown with unclosed inline link destinations. Attackers can submit repeated '[a](' or '![a](' sequences, causing _find_balanced to rescan the remaining document for each link and consume quadratic CPU time.

    References: https://ubuntu.com/security/CVE-2026-118694, https://www.cve.org/CVERecord?id=CVE-2026-118694, https://github.com/trentm/python-markdown2, https://github.com/trentm/python-markdown2/blob/2.5.5/lib/markdown2.py#L1478-L1492, https://github.com/trentm/python-markdown2/blob/2.5.5/lib/markdown2.py#L3029, https://github.com/trentm/python-markdown2/issues/750, https://github.com/trentm/python-markdown2/pull/751, https://www.vulncheck.com/advisories/python-markdown2-through-2.5.5-denial-of-service-via-unclosed-inline-link-destinations

    Affected packages

    Package

    Name: python-markdown2

    Purl: pkg:deb/ubuntu/python-markdown2?arch=source&distro=focal

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -None

    Affected versions

    2.3.7-2

    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
    UBUNTU-CVE-2026-118694 | CVE-DB