CVE-2026-55195
py7zr: Decompression bomb (zip bomb) denial of service via unchecked extraction size
- State
- Published
- Severity
- 8.7 High
- Published
- Jul 8, 2026
- Updated
- Jul 9, 2026
- Reserved
- Jun 16, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | 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 | GitHub_M |
Weaknesses
- CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)
Affected Products
| Product | Versions |
|---|---|
py7zrmiurahr |
|
References
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