JWF edit: More about this now on the Fedora Magazine: The xz package that has already entered the current F40 pre-release versions/variants and rawhide contains malicious code. This does NOT affect users of the Fedora releases (F38, F39 are thus not affected), but all users who use already F40 pre-release versions/variants or rawhide shall read this: Article: CVE details: https://access.redhat.com/security/cve/CVE-2024-3094 Be aware that this is CVE criticality 10: this is the highest ...
If you are on a affected system I would nuke from orbit.