6.2
MEDIUM CVSS 3.1
CVE-2026-44722
pyzipper: Encryption bypass for small files encrypted with pyzipper
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.

INFO

Published Date :

July 17, 2026, 5:17 p.m.

Last Modified :

July 17, 2026, 6:45 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-44722 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM [email protected]
Solution
Update pyzipper to version 0.4.0 to fix an encryption bug exposing checksums.
  • Update pyzipper to version 0.4.0 or later.
  • Ensure AES encryption uses AE-2 format.
  • Verify checksums are not exposed.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-44722.

URL Resource
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
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-44722 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-44722 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-44722 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-44722 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 17, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-44722', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-17T17:25:00.965188Z'}
  • New CVE Received by [email protected]

    Jul. 17, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'danifus', 'product': 'pyzipper', 'versions': [{'status': 'affected', 'version': '< 0.4.0'}]}]
    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.
    Added CVSS V3.1 AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    Added CWE CWE-480
    Added Reference https://github.com/danifus/pyzipper/commit/93ce88e7dfd1635443197dab3fb8d477cff579ae
    Added Reference https://github.com/danifus/pyzipper/releases/tag/v0.4.0
    Added Reference https://github.com/danifus/pyzipper/security/advisories/GHSA-crqm-m339-7m2p
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.