CVE-2020-26035
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn issue was discovered in Zammad before 3.4.1. There is Stored XSS via a Tags element in a TIcket.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA stored Cross-Site Scripting (XSS) vulnerability exists in Zammad helpdesk software versions prior to 3.4.1. The vulnerability allows an attacker to inject malicious JavaScript code through the Tags field when creating or editing a ticket. Since the XSS payload is stored in the database, it executes whenever other users (agents, administrators) view the affected ticket.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 1.0.0, < 3.4.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed Zammad versionRun the command: zammad --version or check the About page in the Zammad web UI under the user menu. Alternatively, inspect the package version if installed via package manager.Affected if The installed version is >= 1.0.0 and < 3.4.1
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Examine ticket tags for suspicious contentAccess the Zammad database and query the tickets table for tags containing HTML or JavaScript characters. In PostgreSQL: SELECT id, title, tags FROM tickets JOIN object_manager_objects ON ... Alternatively, use the API to list tickets and inspect tag values for patterns like <script, javascript:, onload, or other HTML tags.Affected if Any stored tags contain unsanitized HTML or JavaScript code that could execute in a user's browser
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Review recent ticket creation and edit activityCheck the ticket audit log or activity stream for recent ticket modifications, focusing on the tags field. Look for tickets created or edited by users who should not have malicious intent.Affected if Tickets with tags were created or modified recently and those tags contain executable scripts
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Verify ticket creation and edit permissionsNavigate to Zammad admin settings: Roles and Permissions. Identify which roles and users have permission to create or edit tickets.Affected if Untrusted or public-facing users have ticket create/edit permissions, allowing them to inject malicious tags
The environment is affected if Zammad version is below 3.4.1 AND untrusted users can create/edit tickets with tags, or if existing tickets contain malicious script payloads in their tags.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor data3.4.1
Upgrade Zammad to version 3.4.1 or later to obtain the patched version. As a temporary mitigation, restrict ticket creation/edit permissions to trusted users and implement Content Security Policy headers.
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-26035 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-26035 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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