PatchTheCVECVE-2026-64823: Home Assistant Core before 2026.5.4 contains a cross-site scripting vulnerability in the Shelly integration's
CVE-2026-64823 is a medium-severity flaw (CVSS 4.7) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 te
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 4.7 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | Required |
| EPSS exploit chance | 0.3% (top 79%) |
| CISA exploited list | No |
| Weakness | CWE-79 |
| Published | 2026-07-21 |
| Last modified | 2026-10-24 |
Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-64823?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-64823 being exploited?
CVE-2026-64823 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-64823 affect?
CVE-2026-64823 affects affected software. Severity is medium (CVSS 4.7). 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
How urgent is CVE-2026-64823?
Priority 22/100. No elevated risk signals yet.
Software pages
Home Assistant vulnerabilities