Cross-Site Scripting (XSS) in homeassistant (CVE-2026-33044)
Summary
Cross-site scripting in homeassistant (CVE-2026-33044). Risk of unauthorized operations or information disclosure. Exploitable via hours_to_show. Mitigation: upgrade to 2026.01 or later.
Original description
The description as published by the source.
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)
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:
YAML-view of same card:
This issue largely resembles the issue documented in: CVE-2025-62172, but with an entity which can be displayed in a Map, instead of in an energy-dashboard.
PoC
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Register a new sensor (or device) or change the name of an existing one, which provides a location
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Change the name to something malicious, for example
test
For a new entity, it should work when setting the name. For old entities, go here: -
Add the entity to a map card, which has the "hours to show"-attribute set, to display movement history
(The left arrow showing the custom setting, and the right arrow…
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-33044 has been found in homeassistant.
Attackers can target a specific entry point like hours_to_show over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade homeassistant to 2026.01 or later.
If unsure, ask your IT team or search "homeassistant CVE-2026-33044" on the vendor's site.
CVE-2026-33044 (homeassistant) — CWE-79
Attack surface: hours_to_show
Patched: 2026.01 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in homeassistant. Attackers reach the vulnerable code path via hours_to_show.
Check the vendor advisory for the affected versions of homeassistant. Attack surface: hours_to_show.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 2026.01.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'homeassistant' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'homeassistant' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
homeassistantを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade homeassistant to 2026.01ステージング環境で 2026.01 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com