Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. Prior to version 1.18.1, on systems where at least one OCI remote is configured (most common on Fedora systems), a malicious local user in an active local session could use a crafted architecture name to trick the `flatpak-system-helper` process into creating a root-owned directory tree with contents determined by the OCI remote, plus a root-owned `lock` file and `icons` directory, outside the intended root directory. If this vulnerability is combined with other vulnerabilities also fixed in 1.18.1, the combination can lead to local root privilege escalation. This particular vulnerability is not believed to be exploitable if there are no OCI remotes configured (common on non-Fedora systems). Version 1.18.1 patches the issue.