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OpenAdvisories
High · 8.7 CVE-2026-55195 EUVD-2026-42396GHSA-gjrg-mpp7-g774PYSEC-2026-2972

py7zr: Decompression bomb (zip bomb) denial of service via unchecked extraction size

Published Jul 8, 2026 · Updated Jul 9, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
miurahr py7zr < 1.1.3 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 py7zr 1.1.3+dfsg-1 —
Debian 13 py7zr No fix yet —
Debian 12 py7zr No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 py7zr No fix yet —
Ubuntu 26.04 LTS py7zr No fix yet —
Ubuntu 25.10 py7zr No fix yet —
Ubuntu 24.04 LTS py7zr No fix yet —
Ubuntu 22.04 LTS py7zr No fix yet —
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed python-py7zr 1.1.3-1.1 openSUSE-SU-2026:11112-1
openSUSE Leap 16.0 python-py7zr 1.0.0-bp160.2.1 openSUSE-SU-2026:21159-1

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI py7zr < 1.1.3 1.1.3 GHSA-gjrg-mpp7-g774

Advisories 2

References