CVE-2026-34205
Raw vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HSummary
CVE-2026-34205 is a critical-severity Improper Restriction of Communication Channel to Intended Endpoints (CWE-923) vulnerability. Its CVSS base score is 9.6 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Adversary-in-the-Middle (T1557); ranked at the 17th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to IA-3 (Device Identification and Authentication) and SC-23 (Session Authenticity) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-34205 is a vulnerability in Home Assistant, open source home automation software emphasizing local control and privacy. It affects Home Assistant apps (formerly add-ons) configured with host network mode on Linux systems, where unauthenticated endpoints bound to the internal Docker bridge interface are exposed to the local network. This exposure occurs because the configuration fails to restrict access as intended, enabling any device on the same network to reach these endpoints without authentication. The issue, classified under CWE-923, carries a CVSS v3.1 base score of 9.6 (AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H) and was published on 2026-03-27.
An attacker on the adjacent local network can exploit this vulnerability with low attack complexity, requiring no privileges or user interaction. Exploitation allows unauthorized access to the exposed endpoints, potentially resulting in high impacts to confidentiality, integrity, and availability, with a changed scope that could extend compromise beyond the vulnerable component.
Home Assistant Supervisor 2026.03.02 addresses the vulnerability. Additional mitigation details are available in the security advisory at https://github.com/home-assistant/core/security/advisories/GHSA-gh5m-4m97-c95h.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-16793
Vulnerability Data
Home Assistant is open source home automation software that puts local control and privacy first. Home Assistant apps (formerly add-ons) configured with host network mode expose unauthenticated endpoints bound to the internal Docker bridge interface to the local network. On…
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Linux, this configuration does not restrict access to the app as intended, allowing any device on the same network to reach these endpoints without authentication. Home Assistant Supervisor 2026.03.02 addresses the issue.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 5 hardening rules · 3 OS baselines
V8.4.1V10.5.5V12.3.5
Mitigating Controls (NIST 800-53 r5) AI
Requires unique identification and authentication of devices before establishing a communications session.
Enforces authenticity of communication sessions so the system only exchanges data with verified intended endpoints.
Protects transmitted information with cryptographic integrity mechanisms that implicitly verify endpoint identity.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Network segmentation and access controls directly enforce communication only with intended endpoints.
Authenticating services/hardware directly prevents communication with unintended endpoints.
Data-in-transit protections commonly include certificate-based endpoint authentication to ensure correct peers.
Documenting authorized flows helps define intended endpoints but does not enforce channel restrictions at runtime.
Protecting identity assertions supports endpoint verification but is narrower than channel restriction.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure authentication mechanisms ensure the product communicates only with intended, authenticated endpoints.
Network security controls directly enforce endpoint validation and channel restrictions.
Security of network services includes authentication of endpoints and service-to-service channel protection.
Network segregation reduces exposure but does not itself validate specific endpoints.
Cryptography can protect channels but does not guarantee correct endpoint identity without additional controls.
Application security requirements may specify endpoint validation but do not implement it.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-923
- V-248823 OL 8 must not have the telnet-server package installed. prevents CWE-923
RHEL 7 (1 rule)
- V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-923
RHEL 8 (2 rules)
- V-230492 RHEL 8 must not have the rsh-server package installed. prevents CWE-923
- V-230487 RHEL 8 must not have the telnet-server package installed. prevents CWE-923