CVE-2026-44722
pyzipper: Encryption bypass for small files encrypted with pyzipper
- State
- Published
- Severity
- 6.2 Medium
- Published
- Jul 17, 2026
- Updated
- Jul 17, 2026
- Reserved
- May 7, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.2 Medium | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | GitHub_M |
Weaknesses
- CWE-480 Use of Incorrect Operator
Affected Products
| Product | Versions |
|---|---|
pyzipperdanifus |
|
References
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