# Home Assistant: mDNS Server-Side Request Forgery

Advisory record · `GHSA-4ghv-53cq-7wp3`

- **Identifiers:** `GHSA-4ghv-53cq-7wp3` · `CVE-2026-91129` · `PYSEC-2026-4051`
- **State:** Confirmed
- **Severity:** CVSS 5.4 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-918](https://cwe.mitre.org/data/definitions/918.html)
- **Tags:** [Server-side request forgery (SSRF)](https://agentprime.io/advisories/tag/ssrf.md)
- **Published:** 22 Sept 2026
- **Updated:** 1 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 22 Sept 2026, 20:40 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `homeassistant` (PyPI): affected `<2026.2.3`; fixed in `2026.2.3`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Home Assistant versions before 2026.2.3 are vulnerable to a server-side request forgery through the IPP integration's automatic mDNS discovery of \_ipp.\_tcp.local services. An unauthenticated attacker on the same local network can send a crafted mDNS response that makes Home Assistant send HTTP requests, including redirected requests, to arbitrary hosts such as localhost-bound internal services. Upgrade to Home Assistant 2026.2.3 or later, which blocks redirects from non-loopback hosts to loopback addresses.

Written 1 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 5.4 Medium, CVSS 3.1: `CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0029, the 22nd percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:09 UTC: First seen by agentprime
- 31 Oct 2026, 14:09 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-4ghv-53cq-7wp3)

## Sources

- [GitHub Advisory Database: GHSA-4ghv-53cq-7wp3](https://github.com/advisories/GHSA-4ghv-53cq-7wp3)
- [OSV: GHSA-4ghv-53cq-7wp3](https://osv.dev/vulnerability/GHSA-4ghv-53cq-7wp3)
- <https://github.com/home-assistant/core/security/advisories/GHSA-4ghv-53cq-7wp3>
- <https://github.com/home-assistant/core/pull/162941>
- <https://github.com/home-assistant/core/commit/0f3c7ca2772b605c0f3c09c88f35e527ea6ea560>
- <https://github.com/home-assistant/core/commit/815c708d19aa0c7f59f9ee318b613a5e481a42b3>
- <https://github.com/home-assistant/core>
- <https://github.com/home-assistant/core/releases/tag/2026.2.3>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-4ghv-53cq-7wp3>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

---

The web page: <https://agentprime.io/advisories/GHSA-4ghv-53cq-7wp3/>. Everything for agents: <https://agentprime.io/llms.txt>.