UBUNTU-CVE-2026-55195
py7zr is a Python library for handling 7zip archives. Versions prior to 1.1.3 have a vulnerability in the Worker.decompress() function where the total decompressed size is not tracked. This allows a crafted archive to expand significantly during extraction, potentially exhausting disk or memory resources. The issue is fixed in version 1.1.3.
AI Analysis
Technical Summary
The py7zr library versions before 1.1.3 contain a decompression vulnerability where the Worker.decompress() method does not track the total decompressed size of archive entries. An attacker can craft a .7z archive that appears small but decompresses to a very large size, causing resource exhaustion (disk or memory) during extraction. This can lead to denial of service conditions. The vulnerability is resolved in py7zr version 1.1.3.
Potential Impact
An attacker can supply a maliciously crafted 7zip archive that decompresses to a much larger size than the archive itself, exhausting system disk space or memory during extraction. This can cause denial of service by resource exhaustion. There is no indication of code execution or data corruption beyond resource exhaustion.
Mitigation Recommendations
Upgrade py7zr to version 1.1.3 or later, where this decompression size tracking issue is fixed. No other mitigations are indicated. Patch status is confirmed fixed in version 1.1.3.
UBUNTU-CVE-2026-55195
Description
py7zr is a Python library for handling 7zip archives. Versions prior to 1.1.3 have a vulnerability in the Worker.decompress() function where the total decompressed size is not tracked. This allows a crafted archive to expand significantly during extraction, potentially exhausting disk or memory resources. The issue is fixed in version 1.1.3.
CVSS v4.0
Affected software
pkg:deb/ubuntu/[email protected]+dfsg-4ubuntu0.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]+dfsg-8build1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]+dfsg1-1?arch=source&distro=questingpkg:deb/ubuntu/[email protected]+dfsg-1?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The py7zr library versions before 1.1.3 contain a decompression vulnerability where the Worker.decompress() method does not track the total decompressed size of archive entries. An attacker can craft a .7z archive that appears small but decompresses to a very large size, causing resource exhaustion (disk or memory) during extraction. This can lead to denial of service conditions. The vulnerability is resolved in py7zr version 1.1.3.
Potential Impact
An attacker can supply a maliciously crafted 7zip archive that decompresses to a much larger size than the archive itself, exhausting system disk space or memory during extraction. This can cause denial of service by resource exhaustion. There is no indication of code execution or data corruption beyond resource exhaustion.
Mitigation Recommendations
Upgrade py7zr to version 1.1.3 or later, where this decompression size tracking issue is fixed. No other mitigations are indicated. Patch status is confirmed fixed in version 1.1.3.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-55195
- Osv Schema Version
- 1.7.0
- Aliases
- []
- Ecosystems
- ["Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:25.10","Ubuntu:26.04:LTS"]
- Database Specific Severity
- null
- Cvss Version
- 4.0
Threat ID: 6a58b47868715ace43d98130
Added to database: 07/16/2026, 10:37:44 UTC
Last enriched: 07/16/2026, 11:53:14 UTC
Last updated: 07/31/2026, 19:24:49 UTC
Views: 4
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