CVE-2026-70657: Copyparty: file/dirkey confusion

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-18 · updated 2026-10-22
Weakness: CWE-863

Description

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. This vulnerability was only reachable if both types of keys (filekeys and dirkeys) were manually enabled in the volume flags simultaneously. This issue is fixed in version 1.20.17.

Affected products

9001 copyparty: before 1.20.17

References

https://github.com/9001/copyparty/commit/e40755331ba9449993ff482456e6bdd2c6deb950
https://github.com/9001/copyparty/releases/tag/v1.20.17
https://github.com/9001/copyparty/security/advisories/GHSA-x5pq-m9p8-f4vx

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