Logo
-

Byte Open Security

(ByteOS Network)

Log In

Sign Up

ByteOS

Security
Vulnerability Details
Registries
Custom Views
Weaknesses
Attack Patterns
Filters & Tools
Vulnerability Details :

CVE-2026-44722

Summary
Assigner-GitHub_M
Assigner Org ID-a0819718-46f1-4df5-94e2-005712e83aaa
Published At-17 Jul, 2026 | 16:42
Updated At-17 Jul, 2026 | 17:25
Rejected At-
Credits

pyzipper: Encryption bypass for small files encrypted with pyzipper

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.

Vendors
-
Not available
Products
-
Metrics (CVSS)
VersionBase scoreBase severityVector
Weaknesses
Attack Patterns
Solution/Workaround
References
HyperlinkResource Type
EPSS History
Score
Latest Score
-
N/A
No data available for selected date range
Percentile
Latest Percentile
-
N/A
No data available for selected date range
Stakeholder-Specific Vulnerability Categorization (SSVC)
▼Common Vulnerabilities and Exposures (CVE)
cve.org
Assigner:GitHub_M
Assigner Org ID:a0819718-46f1-4df5-94e2-005712e83aaa
Published At:17 Jul, 2026 | 16:42
Updated At:17 Jul, 2026 | 17:25
Rejected At:
▼CVE Numbering Authority (CNA)
pyzipper: Encryption bypass for small files encrypted with pyzipper

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.

Affected Products
Vendor
danifus
Product
pyzipper
Versions
Affected
  • < 0.4.0
Problem Types
TypeCWE IDDescription
CWECWE-480CWE-480: Use of Incorrect Operator
Type: CWE
CWE ID: CWE-480
Description: CWE-480: Use of Incorrect Operator
Metrics
VersionBase scoreBase severityVector
3.16.2MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Version: 3.1
Base score: 6.2
Base severity: MEDIUM
Vector:
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions

Configurations

Workarounds

Exploits

Credits

Timeline
EventDate
Replaced By

Rejected Reason

References
HyperlinkResource
https://github.com/danifus/pyzipper/security/advisories/GHSA-crqm-m339-7m2p
x_refsource_CONFIRM
https://github.com/danifus/pyzipper/commit/93ce88e7dfd1635443197dab3fb8d477cff579ae
x_refsource_MISC
https://github.com/danifus/pyzipper/releases/tag/v0.4.0
x_refsource_MISC
Hyperlink: https://github.com/danifus/pyzipper/security/advisories/GHSA-crqm-m339-7m2p
Resource:
x_refsource_CONFIRM
Hyperlink: https://github.com/danifus/pyzipper/commit/93ce88e7dfd1635443197dab3fb8d477cff579ae
Resource:
x_refsource_MISC
Hyperlink: https://github.com/danifus/pyzipper/releases/tag/v0.4.0
Resource:
x_refsource_MISC
▼Authorized Data Publishers (ADP)
CISA ADP Vulnrichment
Affected Products
Metrics
VersionBase scoreBase severityVector
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions

Configurations

Workarounds

Exploits

Credits

Timeline
EventDate
Replaced By

Rejected Reason

References
HyperlinkResource
Information is not available yet
▼National Vulnerability Database (NVD)
nvd.nist.gov
Source:security-advisories@github.com
Published At:17 Jul, 2026 | 17:17
Updated At:17 Jul, 2026 | 18:45

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.

CISA Catalog
Date AddedDue DateVulnerability NameRequired Action
N/A
Date Added: N/A
Due Date: N/A
Vulnerability Name: N/A
Required Action: N/A
Metrics
TypeVersionBase scoreBase severityVector
Secondary3.16.2MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
N/A
Type: Secondary
Version: 3.1
Base score: 6.2
Base severity: MEDIUM
Vector:
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Type: N/A
Version:
Base score:
Base severity: N/A
Vector:
CPE Matches

Weaknesses
CWE IDTypeSource
CWE-480Secondarysecurity-advisories@github.com
CWE ID: CWE-480
Type: Secondary
Source: security-advisories@github.com
Evaluator Description

Evaluator Impact

Evaluator Solution

Vendor Statements

References
HyperlinkSourceResource
https://github.com/danifus/pyzipper/commit/93ce88e7dfd1635443197dab3fb8d477cff579aesecurity-advisories@github.com
N/A
https://github.com/danifus/pyzipper/releases/tag/v0.4.0security-advisories@github.com
N/A
https://github.com/danifus/pyzipper/security/advisories/GHSA-crqm-m339-7m2psecurity-advisories@github.com
N/A
Hyperlink: https://github.com/danifus/pyzipper/commit/93ce88e7dfd1635443197dab3fb8d477cff579ae
Source: security-advisories@github.com
Resource: N/A
Hyperlink: https://github.com/danifus/pyzipper/releases/tag/v0.4.0
Source: security-advisories@github.com
Resource: N/A
Hyperlink: https://github.com/danifus/pyzipper/security/advisories/GHSA-crqm-m339-7m2p
Source: security-advisories@github.com
Resource: N/A

Change History

0
Information is not available yet

Similar CVEs

0Records found

Details not found