GitHub Security Advisory: GHSA-r584-6283-p7xc
Package: homeassistant (PIP)
Severity: LOW (CVSS 0.0)
CWE: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
Vulnerable versions: >= 2020.02, < 2026.01
Patched in: 2026.01

Summary: Home Assistant has stored XSS in Map-card through malicious device name

Details:
### Summary
An authenticated party can add a malicious name to their device entity, allowing for Cross-Site Scripting attacks against anyone who can see a dashboard with a Map-card which includes that entity. It requires that the victim hovers over an information point (The lines or the dots representing that device's movement, as shown in the screenshot below, with the example showing a html-injection using `
` to strikethrough the text)
<img width="348" height="355" alt="image" src="https://github.com/user-attachments/assets/1af3ef33-3a72-4816-8ade-e6405aace176" />

This allows an authenticated user to execute JavaScript in the context of any other users accessing a dashboard.

### Details

The vulnerability exists in the map-card by adding a malicious entity and having the property `hours_to_show` set.
See example below, with the malicious entity being `Pixel 9 
 Fold Robin {{7*7}}`:
Map card with malicious device entity:
<img width="338" height="332" alt="image" src="https://github.com/user-attachments/assets/15229cc3-1b69-438c-9ee5-cbfa9483aec9" />

YAML-view of same card:
<img width="338" height="198" alt="image" src="https://github.com/user-attachments/assets/cd579266-75c3-4cdf-9d08-1544a6887feb" />


This issue largely resembles the issue documented in: [CVE-2025-62172](https://github.com/home-assistant/core/security/advisories/GHSA-mq77-rv97-285m), but with an entity which can be displayed in a Map, instead of in an energy-dashboard.


### 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:
<img width="1300" height="411" alt="image" src="https://github.com/user-attachments/assets/d240549e-f26c-4617-89d7-5480451ae5a3" />
<img width="1383" height="885" alt="image" src="https://github.com/user-attachments/assets/94db6186-ad54-476c-92a3-9f6870b0c862" />
<img width="387" height="436" alt="image" src="https://github.com/user-attachments/assets/f4c4b9f6-b1e7-4b50-9012-3be31c617be4" />
<br>
<img width="392" height="515" alt="image" src="https://github.com/user-attachments/assets/a0f24d2f-cc18-4ef7-9071-40376dbb38c1" />

3. Add the entity to a map card, which has the "hours to show"-attribute set, to display movement history
<img width="296" height="383" alt="image" src="https://github.com/user-attachments/assets/b2db55b6-3d4b-4ab0-91fe-fc26813ad5ff" />
<img width="692" height="410" alt="image" src="https://github.com/user-attachments/assets/aec15e07-12c0-4abf-ba73-979736131c7c" />

<img width="694" height="302" alt="image" src="https://github.com/user-attachments/assets/e4bb7cac-fe85-41eb-963c-1743e78d937c" />

(The left arrow showing the custom setting, and the right arrow showing a data point which needs to be hovered)

4. The payload executes when hovering a data-point (here shown with an "alert(doc