Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-23879— py7zr: Arbitrary File Write Vulnerability

Quick assessment

Affected
miurahr py7zr
Exploitation
Public or AI PoC available; prioritize validation
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Hiroshi Miura py7zr是日本Hiroshi Miura个人开发者的一个7z文件压缩解压的Python库。 Hiroshi Miura py7zr 1.1.2版本及之前版本存在后置链接漏洞，该漏洞源于任意文件写入问题，攻击者通过特制恶意符号链接链可绕过解压目录边界限制，导致在主机文件系统上写入任意文件，可能导致远程代码执行、权限提升、数据损坏或拒绝服务。

CVSS 8.0 · High EPSS 0.57% · P45

Affected Version Matrix 1

VendorProduct Version RangeStatus
miurahr py7zr < 1.1.3 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-23879

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
py7zr: Arbitrary File Write Vulnerability
Source: CVE Program / CVE List V5
Vulnerability Description
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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
在文件访问前对链接解析不恰当(链接跟随)
Source: CVE Program / CVE List V5
Vulnerability Title
Hiroshi Miura py7zr 后置链接漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Hiroshi Miura py7zr是日本Hiroshi Miura个人开发者的一个7z文件压缩解压的Python库。 Hiroshi Miura py7zr 1.1.2版本及之前版本存在后置链接漏洞，该漏洞源于任意文件写入问题，攻击者通过特制恶意符号链接链可绕过解压目录边界限制，导致在主机文件系统上写入任意文件，可能导致远程代码执行、权限提升、数据损坏或拒绝服务。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
miurahr py7zr < 1.1.3 -

II. Public POCs for CVE-2026-23879

# POC Description Source Link Shenlong Link
AI-Generated POC Premium
Qwen3.6-35B-A3B · 13885 chars
Pro+ exclusive includes:
Vulnerability reproduction recording (real sandbox build + trigger, exclusive)
In-depth vulnerability mechanism
Trigger conditions & impact
Full executable POC code
Exploit chain & mitigation
POC zip download
100+ AI POC generations per month

III. Intelligence Information for CVE-2026-23879

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-23879 (1)

Vendor Advisories for CVE-2026-23879 (1)

IV. Related Vulnerabilities

Same product: py7zr
Same vendor: miurahr
Same weakness: CWE-59

V. Comments for CVE-2026-23879

No comments yet

Leave a comment