PYSEC-2026-440

    Dashboard / Vulnerabilities / PYSEC-2026-440

    PYSEC-2026-440

    Published: 29 Jun 2026Last Modified: 2 Jul 2026

    Summary: OpenStack os-vif Ageing time of 0 disables linuxbridge MAC learning

    Details: In OpenStack os-vif 1.15.x before 1.15.2, and 1.16.0, a hard-coded MAC aging time of 0 disables MAC learning in linuxbridge, forcing obligatory Ethernet flooding of non-local destinations, which both impedes network performance and allows users to possibly view the content of packets for instances belonging to other tenants sharing the same network. Only deployments using the linuxbridge backend are affected. This occurs in PyRoute2.add() in `internal/command/ip/linux/impl_pyroute2.py`.

    References: https://nvd.nist.gov/vuln/detail/CVE-2019-15753, https://github.com/openstack/os-vif/commit/655c83d706f5de8a8cf23430782e065219297aef, https://github.com/openstack/os-vif/commit/ec9d5430300c908ea9a1c64151eee7af522a44e7, https://github.com/openstack/os-vif, https://launchpad.net/bugs/1837252, https://review.opendev.org/672834, https://review.opendev.org/678098, https://security.openstack.org/ossa/OSSA-2019-004.html, http://www.openwall.com/lists/oss-security/2019/08/29/2, https://pypi.org/project/os-vif, https://github.com/advisories/GHSA-mcpw-cp35-p3h8

    Affected packages

    Package

    Name: os-vif

    Purl: pkg:pypi/os-vif

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 1.15.0
    Fixed -1.15.2

    Affected versions

    1.15.0
    1.15.1

    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