Link Following Affecting py7zr package, versions <1.1.2+dfsg-1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-DEBIANUNSTABLE-PY7ZR-17588822
- published27 Jun 2026
- disclosed24 Jun 2026
Introduced: 24 Jun 2026
CVE-2026-23879 (opens in a new tab)How to fix?
Upgrade Debian:unstable py7zr to version 1.1.2+dfsg-1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream py7zr package and not the py7zr package as distributed by Debian.
See How to fix? for Debian:unstable relevant fixed versions and status.
py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Versions 1.1.2 and below contain an an arbitrary file write vulnerability, which allows symbolic links to be recreated outside the destination directory via crafted malicious symbolic link chains. When using extractall to extract an archive, the library restores these symbolic links, linking them to arbitrary directories on the host file system. During extraction, the program only checks the link arcname within the destination directory, but ignores the combined symlink path resolution. Attackers can exploit this vulnerability by constructing malicious archives, thereby bypassing the directory boundary restrictions implemented by the extractor. Subsequent extraction of regular files through these symbolic links can result in arbitrary file writes. This vulnerability may lead to remote code execution, privilege escalation, data corruption, or denial of service. This issue has been fixed in version 1.1.3.