CVE-2026-34155: falha de alta gravidade em rauc

RAUC controls the update process on embedded Linux systems. Prior to version 1.15.2, RAUC bundles using the 'plain' format exceeding a payload size of 2 GiB cause an integer overflow which results in a signature which covers only the first few bytes of the payload. Given such a bundle with a legitimate signature, an attacker can modify the part of the payload which is not covered by the signature. This issue has been patched in version 1.15.2.