A flaw was found in rpmbuild. When rpmbuild processes a crafted tarball in tarball mode, a specially designed tar member name can lead to macro injection. This vulnerability allows a remote attacker to execute arbitrary code on the system by convincing a user to build a malicious tarball.
Do not process untrusted tarballs with rpmbuild -ta/-tb/-ts. Extract and inspect archives first (reject member names containing }, %, or {), or build from a reviewed .spec outside tarball mode. Prefer isolated builders (mock/container) for any untrusted packaging related work.