---
id: "CVE-2026-120331"
kind: "vulnerability"
aliases: ["CVE-2026-120331"]
title: "Mail module fetches external URLs without host checks, enabling internal requests"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["mail-module", "other", "self-hosted"]
not_affected_if: ["backend-access-restricted", "mail-module-unused"]
published_at: "2026-11-03T10:17:17+00:00"
first_seen_at: "2026-11-03T10:20:16+00:00"
updated_at: "2026-11-03T10:20:39+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-120331", "first_seen_at": "2026-11-03T10:20:16+00:00"}]
---

# Mail module fetches external URLs without host checks, enabling internal requests

The server fetches the contents, stylesheets and images of external URL mails without validating the target host. A backend user with access to the mail module can make the server send requests to hosts on the internal network (server-side request forgery).

_Summary, check and fix written by a model from the sources; labelled as such._

## Timeline

- 2026-11-03T10:20:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-120331

## From the sources

Content of external URL mails, their stylesheets and images to embed is fetched by the server without validating the target host. Backend users with access to the mail module can make the server send requests to hosts in the internal network.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_