---
id: CVE-2026-84465
title: Zammad is a web based open source helpdesk/customer support system
summary: >-
  Zammad is a web based open source helpdesk/customer support system. Prior to
  7.1.2, when Zammad checks the digital signature on an incoming S/MIME-signed
  email, it does not verify that the signing certificate is genuinely trusted,
  it onl…
severity: high
cvss: 7.1
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-290
  - CWE-295
  - CWE-347
vendor: zammad
product: zammad
affected:
  - zammad < 7.1.2
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T19:17:58.123'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84465'
references:
  - url: >-
      https://github.com/zammad/zammad/commit/9a07d0b8214ac4e8e10c23fce71d613bd0625524
    label: security-advisories@github.com
  - url: 'https://github.com/zammad/zammad/security/advisories/GHSA-m9ff-hjr3-93h4'
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-09-25T19:15:39.030Z'
---

## Overview

Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, when Zammad checks the digital signature on an incoming S/MIME-signed email, it does not verify that the signing certificate is genuinely trusted, it only checks whether a certificate with a matching name is already stored in the system. An attacker can create their own certificate using the name of a real, previously trusted sender and use it to send a forged email. Zammad will display that email with the same "validly signed" indicator as a genuine message from the real sender, even though the attacker never had access to that sender's actual certificate or private key. This issue is fixed in version 7.1.2.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.