CVE-2026-23879

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-24 20:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-25 22:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 8.0 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-06-24 20:16 UTC

Last modified

2026-10-25 22:10 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-59

Record status

Deferred

Attack profile CVSS 3.1 · 8.0

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-23879.md and follow it. Check whether this project is affected by CVE-2026-23879. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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