CVE-2026-28407: malcontent: Nested archive extraction failure can drop content from scan inputs

Previously, malcontent would remove nested archives which failed to extract which could potentially leave malicious content. A better approach is to preserve these archives so that malcontent can attempt a best-effort scan of the archive bytes.

Fix: https://github.com/chainguard-dev/malcontent/pull/1383

Acknowledgements

malcontent thanks Oleh Konko from 1seal for discovering and reporting this issue.