CVE-2026-44722

pyzipper is a replacement for Python's zipfile that can read and write AES encrypted zip files. Prior to 0.4.0, a Python operator precedence bug in pyzipper/zipfile_aes.py caused the AE-2 format to never be automatically selected during encryption, causing encrypted entries to be written in AE-1 format and exposing the plaintext CRC32 checksum in the ZIP header and, for unseekable zip archives, in the datadescripter section, allowing an attacker who possesses the archive to brute-force candidate plaintexts for small or low-entropy files by comparing CRC32 values. This issue is fixed in version 0.4.0.

CVSS 3.1

6.2CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

0.1% chance of exploitation in the next 30 days; higher than 1% of CVEs (scores of 2026-10-25)

CWE

CWE-480

Published

2026-07-17

Modified

2026-10-24

Record from

the NVD, synced 2026-10-25

Packages (OSV)

References

• https://github.com/danifus/pyzipper/commit/93ce88e7dfd1635443197dab3fb8d477cff579ae
• https://github.com/danifus/pyzipper/releases/tag/v0.4.0
• https://github.com/danifus/pyzipper/security/advisories/GHSA-crqm-m339-7m2p

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