CVE-2023-41896Public exploitNetwork attack vector

Instance takeover via untrusted WebSocket backend

Published Oct 19, 2023 · Updated Sep 12, 2024

Cross-site scripting in Home Assistant Core before 2023.8.0 allows context-dependent attackers to take over an instance via a crafted link. The auth_callback WebSocket flow decodes an attacker-controlled state value and trusts its hassUrl, connecting the frontend to a spoofed backend whose custom-panel js_url response executes script on the genuine origin. A victim must open the link; successful script execution can use the genuine frontend's access to the real backend to control the instance.

CVSS severity7.1
High
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Home Assistant Core before 2023.8.0 allows context-dependent attackers to take over an instance via a crafted link. The auth_callback WebSocket flow decodes an attacker-controlled state value and trusts its hassUrl, connecting the frontend to a spoofed backend whose custom-panel js_url response executes script on the genuine origin. A victim must open the link; successful script execution can use the genuine frontend's access to the real backend to control the instance.

The record

CVE
CVE-2023-41896
Published
Oct 19, 2023
Updated
Sep 12, 2024
Vendor
Home Assistant
Product
Home Assistant Core
Classifications
CWE-345, T1204.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 19, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 12, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=Home Assistant Core : < 2023.8.0
  2. Affected versionversion=home-assistant-js-websocket: < 8.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Home Assistant · Home Assistant Coreversion=Home Assistant Core : < 2023.8.0; version=home-assistant-js-websocket: < 8.2.0

Published CVSS scores

7.1GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
9.0NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitPublished

Weakness, pattern, technique

CWE-345Insufficient Verification of Data Authenticity
T1204.001User Execution: Malicious Link

Public exploit references

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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