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.
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| danifus | pyzipper | affected |
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Remediation
No remediation available yet.
Tracking
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Advisories
| Source | ID | Title |
|---|---|---|
 Github GHSA |
GHSA-crqm-m339-7m2p | pyzipper has an encryption bypass for small files encrypted using it |
References
History
Fri, 17 Jul 2026 16:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | pyzipper: Encryption bypass for small files encrypted with pyzipper | |
| Weaknesses | CWE-480 | |
| References |
| |
| Metrics |
cvssV3_1
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Subscriptions
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MITRE
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-07-17T17:25:08.270Z
Reserved: 2026-05-07T18:04:17.308Z
Link: CVE-2026-44722
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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Weaknesses
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CWE-480
Use of Incorrect Operator