Zammad: Remote image tracking bypass via shortened URL scheme
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
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 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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Zammad GmbH | zammad | before 7.1.2 | 7.1.2 | Patch available | CNA |
- zammad VendorZammad GmbH Affected before 7.1.2 Fixed in 7.1.2 Patch available CNA
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:zammad:zammad:*:*:*:*:*:*:*:* | — | — | Zammad GmbH |
- cpe:2.3:a:zammad:zammad:*:*:*:*:*:*:*:* Versions — — ·Zammad GmbH
Remediation
- Fix · CNA zammad (zammad) Fixed in 7.1.2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-63206
References
More Zammad GmbH vulnerabilities
- TI-2026-65406 Local privilege escalation in Zammad v1.5.0 to v7.2.2 installed via DEB or RPM package KEVCVSS 4.0CRITICAL 9.4
- TI-2026-65405 Undisclosed RCE in Zammad v6.3 and higher KEVCVSS 4.0CRITICAL 9.4
- TI-2024-22252 An issue was discovered in Zammad before 6.3.0. CVSS 3.1CRITICAL 9.1
- TI-2026-11233 Zammad 7.0.1 - Improper authorization in ticket article attachment cloning CVSS 4.0HIGH 7.1
- TI-2022-23785 A vulnerability in Zammad v5.3.0 allows attackers to execute arbitrary code or escalate… CVSS 3.1CRITICAL 9.8
- TI-2026-58043 Zammad: Account takeover via unverified email matching during SSO auto-link CVSS 4.0CRITICAL 9.1
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences