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TI-2026-32609 Aliases CVE-2026-44722GHSA-crqm-m339-7m2p

pyzipper: Encryption bypass for small files encrypted with pyzipper

Priority LOW 26CWE-480Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00116 1st percentileScored 2026-11-07
Fix Fixed pyzipper (danifus): 0.4.0pyzipper (PyPI): 0.4.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
danifuspyzipperbefore 0.4.00.4.0Patch availableCNA
—pyzipper (PyPI)before 0.4.00.4.0Patch availableGHSA-crqm-m339-7m2p
  • pyzipper Vendordanifus Affected before 0.4.0 Fixed in 0.4.0 Patch available CNA
  • pyzipper (PyPI) Vendor— Affected before 0.4.0 Fixed in 0.4.0 Patch available GHSA-crqm-m339-7m2p

Remediation

  • Fix · CNA pyzipper (danifus) Fixed in 0.4.0
  • Fix · GHSA-crqm-m339-7m2p pyzipper (PyPI) Fixed in 0.4.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-44722
  2. 2026-10-03 Alias added: GHSA-crqm-m339-7m2p

References

Other 4

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences