PYSEC-2026-3044 pyzipper has an encryption bypass for small files encrypted using it

Impact A Python operator precedence bug in pyzipper/zipfileaes.py caused the AE-2 format to never be automatically selected during encryption, regardless of file size or compression type. As a result, all encrypted entries are written in AE-1 format unless AE-2 is explicitly forced by the caller...

pyzipper has an encryption bypass for small files encrypted using it

ImpactA Python operator precedence bug in pyzipper/zipfileaes.py caused the AE-2 format to never be automatically selected during encryption, regardless of file size or compression type. As a result, all encrypted entries are written in AE-1 format unless AE-2 is explicitly forced by the caller...