py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, PackInfo._read() in archiveinfo.py used an O(n^2) cumulative sum pattern for attacker-controlled numstreams values parsed from archive headers, allowing a crafted .7z archive to cause excessive CPU consumption during SevenZipFile.init() before extraction. This issue is fixed in version 1.1.3.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption     and decryption. Prior to 1.1.3, PackInfo._read() in archiveinfo.py used an O(n^2) cumulative sum pattern     for attacker-controlled numstreams values parsed from archive headers, allowing a crafted .7z archive to     cause excessive CPU consumption during SevenZipFile.init() before extraction. This issue is fixed in     version 1.1.3. (CVE-2026-55206)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote openSUSE 16 host has a package installed that is affected by multiple vulnerabilities as referenced in the openSUSE-SU-2026:21159-1 advisory.

    Changes in python-py7zr:

    - CVE-2026-23879: crafted malicious symbolic link chains in an archive can       lead to an arbitrary file write (bsc#1268669)
    - CVE-2026-55195: unchecked extraction size can cause a denial of service (bsc#1268665)
    - CVE-2026-55206: crafted .7z archive with a large numstreams value can       cause a denial of service (bsc#1268666)

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption
    and decryption. Prior to 1.1.3, PackInfo._read() in archiveinfo.py used an O(n^2) cumulative sum pattern
    for attacker-controlled numstreams values parsed from archive headers, allowing a crafted .7z archive to
    cause excessive CPU consumption during SevenZipFile.init() before extraction. This issue is fixed in
    version 1.1.3. (CVE-2026-55206)

ID	Name	Product	Family	Type	Severity
326080	Linux Distros Unpatched Vulnerability : CVE-2026-55206	Nessus	Misc.	Local	high
324069	openSUSE 16 Security Update : python-py7zr (openSUSE-SU-2026:21159-1)	Nessus	SuSE Local Security Checks	Local	high
443615	SCA: security update for py7zr (GHSA-h4gh-22qq-72r7)	Tenable Cloud Security	SCA Checks	Local	high
443615	SCA: security update for py7zr (GHSA-h4gh-22qq-72r7)	Tenable Self-Hosted Container Security	SCA Checks	Local	high

Detections

Analytics

CVE-2026-55206

high

Tenable Plugins

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high

high

high