CVE-2026-33045Public exploitNetwork attack vector

Session takeover via unescaped history-graph sensor names

Published Mar 27, 2026 · Updated Mar 27, 2026

Stored XSS in Home Assistant Core 2025.02 through 2025.12 allows remote authenticated users to execute JavaScript in another user's browser. The history-graph card inserts a sensor entity name into a graph tooltip without output escaping or sanitization, so HTML event handlers execute when rendered. A low-privileged user must control the sensor name, a victim must add the sensor to a history graph and hover a data point, and the resulting script can act in that victim's session.

CVSS severity5.4
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

Stored XSS in Home Assistant Core 2025.02 through 2025.12 allows remote authenticated users to execute JavaScript in another user's browser. The history-graph card inserts a sensor entity name into a graph tooltip without output escaping or sanitization, so HTML event handlers execute when rendered. A low-privileged user must control the sensor name, a victim must add the sensor to a history graph and hover a data point, and the resulting script can act in that victim's session.

The record

CVE
CVE-2026-33045
Published
Mar 27, 2026
Updated
Mar 27, 2026
Vendor
Home Assistant
Product
Home Assistant Core
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 27, 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=>= 2025.02, < 2026.01

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Home Assistant · Home Assistant Coreversion=>= 2025.02, < 2026.01

Published CVSS scores

7.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript/JScript

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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