Description
py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, py7zr's Worker.decompress() extracted archive entries without tracking total decompressed size, allowing a crafted .7z file such as a 15.6 KB archive that expands to 100 MB to exhaust disk or memory before extraction completes. This issue is fixed in version 1.1.3.
Published: 2026-07-08
Score: 8.7 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-gjrg-mpp7-g774 py7zr: Decompression bomb (zip bomb) denial of service via unchecked extraction size
History

Thu, 09 Jul 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 09 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Wed, 08 Jul 2026 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Miurahr
Miurahr py7zr
Vendors & Products Miurahr
Miurahr py7zr

Wed, 08 Jul 2026 20:45:00 +0000

Type Values Removed Values Added
Description py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, py7zr's Worker.decompress() extracted archive entries without tracking total decompressed size, allowing a crafted .7z file such as a 15.6 KB archive that expands to 100 MB to exhaust disk or memory before extraction completes. This issue is fixed in version 1.1.3.
Title py7zr: Decompression bomb (zip bomb) denial of service via unchecked extraction size
Weaknesses CWE-409
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-07-09T14:06:02.499Z

Reserved: 2026-06-16T15:20:43.087Z

Link: CVE-2026-55195

cve-icon Vulnrichment

Updated: 2026-07-09T14:05:45.735Z

cve-icon NVD

No data.

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-08T20:30:58Z

Links: CVE-2026-55195 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-07-09T04:15:12Z

Weaknesses