---
id: CVE-2026-63206
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, zammad's HTML sanitizer, which blocks remote images in ticket articles
  and email views, can be bypassed using a shortened URL format that omits the
  doubl…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-20
  - CWE-184
vendor: zammad
product: zammad
affected:
  - zammad < 7.1.2
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T20:17:29.987'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-63206'
references:
  - url: >-
      https://github.com/zammad/zammad/commit/a5878f37e4010f0b3bec85dae35af964cc1c8019
    label: security-advisories@github.com
  - url: 'https://github.com/zammad/zammad/security/advisories/GHSA-fpwp-w2p4-hqg7'
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-25T19:46:26.256481Z'
cvssSource: cna
ingestedAt: '2026-09-25T19:15:39.034Z'
---

## Overview

Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, zammad's HTML sanitizer, which blocks remote images in ticket articles and email views, can be bypassed using a shortened URL format that omits the double slash after the scheme (for example a shortened HTTP URL instead of a shortened HTTP URL). Modern browsers treat both forms as equivalent remote URLs. As a result, an attacker who sends a crafted email or ticket can cause the recipient's browser to silently load an image from an external server, revealing when and by whom the ticket was opened. Zammad's "remote content blocked" warning is not shown because the sanitizer does not recognize the shortened form as remote. This issue is fixed in version 7.1.2.

## Remediation

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