CVE-2026-63206
Zammad: Remote image tracking bypass via shortened URL scheme
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | Medium5.3 | 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 |
| NVDNVD · Deferred | 4.0 | Medium5.3 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.28% · top 80% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Weakness
Affected products
References (2)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-63206)Record last updated .