Vulnerability · Published Sep 22, 2026 · Assigned by GitHub_M

CVE-2026-91129Home Assistant: mDNS Server-Side Request Forgery

Medium 5.4

In plain English

A medium-severity server-side request forgery in core from home-assistant. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)0.3%top 77.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

Home Assistant is open source home automation software focused on local control and privacy. Prior to 2026.2.3, the IPP integration automatically processed unauthenticated _ipp._tcp.local mDNS announcements in homeassistant/components/ipp/config_flow.py, where async_step_zeroconf passed attacker-controlled host, port, and base_path values to validate_input for printer metadata retrieval. Because the shared HTTP client followed attacker-controlled cross-origin redirects without blocking loopback targets, a local-network attacker could redirect the request to 127.0.0.1 or another internal service without user interaction or prior IPP configuration. This issue is fixed in version 2026.2.3.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
PyPIhomeassistant2026.2.3GHSA-4ghv-53cq-7wp3
PyPIhomeassistant2026.2.3PYSEC-2026-4051

Affected products (as reported)

VendorProductVersions
home-assistant core < 2026.2.3

Weakness: CWE-918 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References