shadow-utils (aka shadow) 4.4 through 4.17.0 establishes a default /etc/subuid behavior (e.g., uid 100000 through 165535 for the first user account) that can realistically conflict with the uids of users defined on locally administered networks, potentially leading to account takeover, e.g., by leveraging newuidmap for access to an NFS home directory (or same-host resources in the case of remote logins by these local network users). NOTE: it may also be argued that system administrators should not have assigned uids, within local networks, that are within the range that can occur in /etc/subuid.

Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability? One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.