# CVE-2026-63206: Zammad: Remote image tracking bypass via shortened URL scheme

> Attackers can bypass remote image blocking in Zammad using malformed URLs, silently tracking when and by whom tickets are opened.

- **Severity:** Medium 5.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 25 Sep 2026
- **Updated:** 25 Sep 2026
- **Also known as:** GHSA-fpwp-w2p4-hqg7

## What is CVE-2026-63206?

CVE-2026-63206 is a medium-severity vulnerability in zammad, published on 25 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-20 (Improper Input Validation), CWE-184 (Incomplete List of Disallowed Inputs)

## Which versions are affected by CVE-2026-63206?


## How do I fix CVE-2026-63206?

No fix has been published for CVE-2026-63206 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-63206 being exploited?

There is no known exploitation of CVE-2026-63206 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63206 and fix it if it is affected.

What it is: CVE-2026-63206 is a medium-severity vulnerability in zammad, published on 25 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-63206 in the wild and no public exploit code.

Affected product: zammad. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-63206/ (Markdown: https://insights.sbomify.com/CVE-2026-63206/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63206
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63206
- OSV: https://osv.dev/vulnerability/CVE-2026-63206

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63206/
Summaries are generated and may contain mistakes; the official description above is the record.