CVE-2026-70657Network attack vector

Read access via filekey-dirkey confusion

Published Aug 18, 2026 · Updated Aug 19, 2026

Incorrect authorization in 9001 copyparty before 1.20.17 allows attackers to read a containing folder via a crafted file key. In httpcli.py, tx_browser set add_dk from the volume's dk flag even when a request was already using a file key, so a file-key-backed browse response could expose a directory key for the parent folder. Reachability required a non-default volume configuration that manually enabled both dirkeys and filekeys with dk or dks plus fk or fka; the disclosed impact is unauthorized read access to that containing folder.

CVSS severity4.3
Medium
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in 9001 copyparty before 1.20.17 allows attackers to read a containing folder via a crafted file key. In httpcli.py, tx_browser set add_dk from the volume's dk flag even when a request was already using a file key, so a file-key-backed browse response could expose a directory key for the parent folder. Reachability required a non-default volume configuration that manually enabled both dirkeys and filekeys with dk or dks plus fk or fka; the disclosed impact is unauthorized read access to that containing folder.

The record

CVE
CVE-2026-70657
Published
Aug 18, 2026
Updated
Aug 19, 2026
Vendor
copyparty
Product
copyparty
Classifications
CWE-863, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.20.17

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

copyparty · copypartyversion=< 1.20.17

Published CVSS scores

4.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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