CVE-2026-93353 MEDIUM

CVE-2026-93353: copyparty SFTP Volume Restriction Bypass via mkdir/rmdir/chattr Handlers

Vendor 9001
Product copyparty
Weakness CWE-59
Published September 24, 2026
Last update September 25, 2026

CVSS base score

6.0/10
Attack vector Network
Attack complexity High
Privileges required Low
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

copyparty contains a volume restriction bypass vulnerability in its SFTP front end that allows authenticated SFTP users to create, remove, and truncate arbitrary paths outside permitted volume boundaries by exploiting three handlers that bypass the xvol volflag enforcement. The _mkdir, _rmdir, and _chattr handlers construct destination paths using vfs.get(), vn.canonical(), and os.path.join() without invoking the chk_ap access check, enabling attackers to traverse symlinks leaving a volume's top directory and perform unauthorized file creation, deletion, or truncation via SSH_FXP_SETSTAT operations on paths outside any volume the account is authorized to access.

Key dates

02Disclosure timeline

September 24, 2026 CVE published
September 25, 2026 Record updated