CVE-2026-64823

LOW
INFO Priority: 0.01 BB Relevance: 54/100
Published: 2026-07-21 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth

CVSS Vector Breakdown

AV: Network
AC: High
PR: None
UI: Active
S: X
AT: None
VC: None
VI: None
VA: None

Description

Home Assistant Core before 2026.5.4 contains a cross-site scripting vulnerability in the Shelly integration's async_get_media_image() method that allows attackers controlling a Shelly device's thumb field to serve arbitrary HTML content by supplying a data URI with a text/html content type without validation against an image-only allowlist. Attackers can cause the media player proxy endpoint to serve attacker-controlled bytes with Content-Type text/html in the Home Assistant web origin, enabling theft of session tokens from local storage and authenticated calls to sensitive service endpoints including lock, alarm, and cover controls.

Weakness Classification (1)

Bug Bounty Relevance

54 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity

CVSS Score

2.1 / 10.0 v4.0
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.30%
Raw Score 0.002960
Percentile 22.2%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00296
2026-10-28
0.00296

Intelligence Sources

nvd ref →