Auth bypass in 9001 Copyparty
CVE-2026-70657
Copyparty is a portable file server. Prior to 1.20.17, copyparty volumes with the dk or dks directory-key flag combined with the fk or fka file-key flag can convert a valid file key into a directory key, granting read access to the containing folder even though both features are disabled by default and must be explicitly enabled in the volume flags. This issue is fixed in version 1.20.17.
Vulnerability class: Broken Access Control
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
Affected products
- 9001 Copyparty — versions < 1.20.17
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_CONFIRM)
Frequently asked questions
- What is CVE-2026-70657?
- CVE-2026-70657 is a medium-severity vulnerability in 9001 Copyparty, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2026-08-18.
- How severe is CVE-2026-70657?
- Medium severity. CVSS v3 base score is 4.3 out of 10.