Quick answers
- Is CVE-2021-47942 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2021-47942 being exploited in the wild.
- How severe is CVE-2021-47942?
- High severity, with a CVSS score of 7.5, published 16 May 2026.
- Which products and versions are affected?
- Home Assistant Community Store < 1.10.0.
- Is there a fix for CVE-2021-47942?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2021-47942 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2021-47942?
- Check whether you run Home Assistant Community Store at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A path traversal vulnerability (CWE-22) exists in the HACS integration for Home Assistant due to insufficient input validation on the '/hacsfiles/' endpoint. An unauthenticated remote attacker can use directory traversal sequences (e.g., '../../') to escape the intended directory and read arbitrary files from the host system. Specifically, attackers can target the '.storage/auth' file, which contains user credentials and refresh tokens. By extracting these secrets, an attacker can craft valid JSON Web Tokens (JWT) to bypass authentication and achieve full administrative access to the Home Assistant instance. The vulnerability is addressed in HACS version 1.10.0.
Affected products
- Home Assistant Home Assistant Community Store (HACS) < 1.10.0
Timeline
- 2021-01-28: disclosed: Initial exploit published by Lyghtnox
- 2021-01-29: other: Exploit added to Exploit-DB
- 2026-05-16: advisory: NVD and VulnCheck published formal advisory details