CVE-2025-66270

Paired-device impersonation via mismatched discovery packet IDs

Published Dec 5, 2025 · Updated Dec 5, 2025

Authentication bypass in KDE Connect protocol 8 allows adjacent attackers to impersonate a paired device through discovery packets. During version 8 discovery, implementations use the first packet to decide pairing status, then accept a different device ID from the second packet without correlating the identities. An attacker on the same network who knows a previously paired device ID gains that device's privileges, limited to the permissions already granted to it.

CVSS severity4.7
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in KDE Connect protocol 8 allows adjacent attackers to impersonate a paired device through discovery packets. During version 8 discovery, implementations use the first packet to decide pairing status, then accept a different device ID from the second packet without correlating the identities. An attacker on the same network who knows a previously paired device ID gains that device's privileges, limited to the permissions already granted to it.

The record

CVE
CVE-2025-66270
Published
Dec 5, 2025
Updated
Dec 5, 2025
Vendor
KDE
Product
KDE Connect protocol
Classifications
CWE-290
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 5, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 5, 2025Record 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=8

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

KDE · KDE Connect protocolversion=8

Published CVSS scores

4.7MITRECVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:L/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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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