CVE-2026-70657: Copyparty Copyparty Vulnerable To File/dirkey Confusion Vulnerability

MODERATE
Advisory Identifier: GHSA-x5pq-m9p8-f4vx
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CVSS 4.3
CWE-863
Published
Advisory Summary

CVE-2026-70657 is a MODERATE (CVSS 4.3) copyparty vulnerable to file/dirkey confusion vulnerability (CWE-863: Incorrect Authorization) affecting Copyparty libraries in the PyPI ecosystem. The issue involves copyparty vulnerable to file/dirkey confusion. Remediation is available by upgrading affected packages to version 1.20.17.

CVE-2026-70657 at a Glance

CVE Identifier CVE-2026-70657
GHSA Identifier GHSA-x5pq-m9p8-f4vx
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-863: Incorrect Authorization
Affected Product Copyparty
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 4.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-70657

To remediate this vulnerability, upgrade all affected Copyparty dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

copyparty fixed: 1.20.17 
pip install copyparty>=1.20.17
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show copyparty

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-70657, inspect your installed packages using pip:

pip show copyparty

Analyze the terminal output to locate any version of Copyparty in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.20.17), your application is affected.

Note: The pip show copyparty command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In Copyparty, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A valid filekey could potentially be converted into a dirkey, granting read-access to the containing folder. This issue only affected volumes which simultaneously enable both filekeys and dirkeys, with volflag `dk` or `dks` combined with `fk` or `fka`. Both required features are default-disabled, and must be explicitly enabled in the volflags (the "flags" section of a volume).

CVE-2026-70657 Affected Copyparty Versions

1 component(s)
Fixed Versions:
1.20.17
Product / Package Ecosystem Affected Versions Fixed Version
copyparty
pypi/copyparty
PyPI
< 1.20.17
1.20.17

References

GitHub Advisory / Wiki ADVISORY
https://github.com/9001/copyparty/security/advisories/GHSA-x5pq-m9p8-f4vx
Security Fix Commit FIX COMMIT
https://github.com/9001/copyparty/commit/e40755331ba9449993ff482456e6bdd2c6deb950
Copyparty Source Repository REPOSITORY
https://github.com/9001/copyparty
Copyparty Release RELEASE
https://github.com/9001/copyparty/releases/tag/v1.20.17

Frequently Asked Questions

What is CVE-2026-70657?
CVE-2026-70657 is a security vulnerability in Copyparty involving Copyparty vulnerable to file/dirkey confusion under CWE-863: Incorrect Authorization.
Which Copyparty versions are affected?
Affected versions include releases prior to 1.20.17 across affected packages: copyparty.
What version fixes CVE-2026-70657?
Upgrading to 1.20.17 (or the latest patched release for your respective branch) resolves the vulnerability.
Is copyparty affected?
Yes, copyparty is affected in releases prior to 1.20.17. Upgrade your dependency to 1.20.17 or later.
What is the CVSS score of CVE-2026-70657?
CVE-2026-70657 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-70657?
CVE-2026-70657 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check PyPI dependencies for CVE-2026-70657?
Run the dependency tree command: 'pip show copyparty'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-x5pq-m9p8-f4vx",
  "modified" : "2026-08-18T15:02:01Z",
  "published" : "2026-08-18T15:02:01Z",
  "aliases" : [ "CVE-2026-70657" ],
  "summary" : "Copyparty vulnerable to file/dirkey confusion",
  "details" : "A valid filekey could potentially be converted into a dirkey, granting read-access to the containing folder.\n\nThis issue only affected volumes which simultaneously enable both filekeys and dirkeys, with volflag `dk` or `dks` combined with `fk` or `fka`.\n\nBoth required features are default-disabled, and must be explicitly enabled in the volflags (the \"flags\" section of a volume).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "copyparty"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.20.17"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/9001/copyparty/security/advisories/GHSA-x5pq-m9p8-f4vx"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/9001/copyparty/commit/e40755331ba9449993ff482456e6bdd2c6deb950"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/9001/copyparty"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/9001/copyparty/releases/tag/v1.20.17"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-18T15:02:01Z",
    "nvd_published_at" : null
  }
}