CVE-2026-54174melange allows users to build apk packages using declarative pipelines. Apko prior to version 1.2.9, corresponding to melange prior to version 0.50.4, verified the control section hash (`.PKGINFO` etc.) against the signed `APKINDEX`, but never verified the data section hash (the actual package files that get installed). An attacker who could compromise a mirror, poison a cache, or MITM a package fetch could substitute arbitrary file contents while the control hash check still passed. Apko version 1.2.9 and melange version 0.50.4 contain a fix.