---
id: "CVE-2026-123622"
page: "https://infrastack.ai/live/CVE-2026-123622"
kind: "vulnerability"
aliases: ["CVE-2026-123622"]
title: "Usermin: email attachment XSS runs script in logged-in webmail sessions"
severity: "medium"
cvss: 6.1
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["runtime", "self-hosted", "usermin", "webmail"]
not_affected_if: ["mailbox-module-disabled"]
published_at: "2026-11-06T15:17:19+00:00"
first_seen_at: "2026-11-06T15:42:44+00:00"
updated_at: "2026-11-06T15:44:32+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123622", "first_seen_at": "2026-11-06T15:42:44+00:00"}]
exploit_sources: []
---

# Usermin: email attachment XSS runs script in logged-in webmail sessions

Link for people: https://infrastack.ai/live/CVE-2026-123622 (this .md is for agents)

Usermin's mailbox/detach.cgi page does not filter the type parameter, so an HTML attachment or crafted link can run JavaScript in a victim's authenticated Usermin session. An attacker who gets a user to open the link can act as that user inside their mail session.

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

## How to check

- Check the installed Usermin version (for example with `usermin -v` or the package manager) and compare it with the fixed release in the product data.
- Look for `mailbox/detach.cgi` in the Usermin web server access logs with `type=text/html`.

## Timeline

- 2026-11-06T15:42:44+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123622

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/usermin-through-2.570-xss-via-mailbox-detach-cgi-type-parameter
- [fix] Patch: github.com https://github.com/webmin/usermin/commit/c5c43b9ad04a60809ac2eb271bf8f3d0fec2e46a

## From the sources

Usermin through 2.570 contains a cross-site scripting vulnerability in mailbox/detach.cgi that allows remote attackers to execute script by supplying an arbitrary type parameter that bypasses JavaScript filtering. Attackers can email an HTML attachment containing script and lure recipients to a detach.cgi link with type=text/html to run script in the victim's authenticated Usermin session.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_