Skip to content

Home Assistant has stored XSS in history-graphs

Low severity GitHub Reviewed Published Mar 27, 2026 in home-assistant/core • Updated Mar 27, 2026

Package

pip homeassistant (pip)

Affected versions

>= 2025.02, < 2026.01

Patched versions

2026.01

Description

Summary

The "remaining charge time"-sensor for mobile phones (imported/included from Android Auto it appears) is vulnerable to the same issue as CVE-2025-62172.
image
This also indicates that any sensor showing their name in the history-graph, is likely to be vulnerable to this issue.

Details

Another entity was found which displays the same behavior as in this issue: CVE-2025-62172

The History-graph card will sometimes display the name of the entity it is displaying, when the graph is shown as a line with values on the x and y axis. This appears to be vulnerable to Cross-Site scripting (XSS) as it does not have any output escaping or sanitization.

The PoC in this instance only shows HTML-injection in the form of the <s> -tag being rendered as strike through, but the vulnerability also allows for injecting arbitrary tags which execute JavaScript, like the example given in the PoC description below.

PoC

  1. Register a new sensor (or device) or change the name of an existing one, which provides a location
  2. Change the name to something malicious, for example test <img src=x onerror=alert(document.domain) />
    For a new entity, it should work when setting the name. For old entities, go here:

image

image

image


image

PS: the example pictures show changing the name of the device-tracker entity, which is wrong. Just change the name of the remaining charge time-sensor in order to validate this finding

  1. Add a history graph card with the malicious sensor

image

  1. Hover the graph for payload execution

image

Impact

The impact of this vulnerability is that a user can target other users of the system and perform account takeover through client side exploitation of XSS.

In the context of this system, I believe the vulnerability to be less impactful than the CVSS metric describes. It is not displayed anywhere by default, it is not natural to display this history graph, and it also has no potential for being imported through seemingly innocent integrations. It also appears to rely on having used/using Android Auto. Other devices which has the same sensor can trigger the same vulnerability, and I expect there to exists cloud-based devices that would enable a threat actor to deliver the payload remotely.

Credit: Robin Lunde - https://robinlunde.com

References

@bramkragten bramkragten published to home-assistant/core Mar 27, 2026
Published by the National Vulnerability Database Mar 27, 2026
Published to the GitHub Advisory Database Mar 27, 2026
Reviewed Mar 27, 2026
Last updated Mar 27, 2026

Severity

Low

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements Present
Privileges Required Low
User interaction Active
Vulnerable System Impact Metrics
Confidentiality Low
Integrity Low
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:P

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(14th percentile)

Weaknesses

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Learn more on MITRE.

CVE ID

CVE-2026-33045

GHSA ID

GHSA-46j8-vpx8-6p72

Source code

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.