Inefficient Algorithmic Complexity Affecting py7zr package, versions [,1.1.3)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-PY7ZR-17391449
- published21 Jun 2026
- disclosed19 Jun 2026
- creditHunSec
Introduced: 19 Jun 2026
CVE-2026-55206 (opens in a new tab)How to fix?
Upgrade py7zr to version 1.1.3 or higher.
Overview
py7zr is a Pure python 7-zip library
Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity through the PackInfo._read function. An attacker can cause excessive CPU consumption by providing a crafted archive with a large number of streams, leading to significant performance degradation during archive header parsing.