GitLabApplication
CVE-2020-13262
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 · uneditedClient-Side code injection through Mermaid markup in GitLab CE/EE 12.9 and later through 13.0.1 allows a specially crafted Mermaid payload to PUT requests on behalf of other users via clicking on a link
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 confidenceGitLab CE/EE versions 12.9 through 13.0.1 are vulnerable to client-side code injection via Mermaid markup. Attackers can craft malicious Mermaid diagram definitions that, when rendered and clicked by a victim, trigger unauthorized PUT requests on behalf of that user. This is a CSRF-like attack leveraging the Mermaid diagram rendering component.
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
GitLabApplication
>= 12.9.0, < 12.9.8>= 12.10.0, < 12.10.7= 13.0.0CVSS 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
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/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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Check GitLab versionNavigate to the GitLab Admin area (or /help page) to find the installed version, or run `gitlab-rake gitlab:env:info` from the server command lineAffected if The version falls within 12.9.0 to 12.9.7, 12.10.0 to 12.10.6, or exactly 13.0.0
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Identify if Mermaid is in useSearch GitLab repositories, wikis, or markdown files for Mermaid diagram syntax (look for code blocks labeled `mermaid` or ```mermaid blocks containing graph, sequenceDiagram, or other Mermaid diagram definitionsAffected if Mermaid diagram markup exists in any project, snippet, or wiki content within the GitLab instance
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Review Mermaid content for suspicious elementsExamine any Mermaid diagram definitions for unusual JavaScript-like behavior, onclick handlers, or URL patterns that could indicate malicious payload designed to trigger unauthorized PUT requestsAffected if Any Mermaid content contains suspicious link definitions or event handlers that could perform cross-site request forgery actions
You are affected if your GitLab version is 12.9.0-12.9.7, 12.10.0-12.10.6, or 13.0.0 AND Mermaid diagrams are rendered within your instance.
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 data12.9.812.10.7
Upgrade GitLab to version 13.0.2 or later. As a workaround, disable Mermaid diagram rendering in affected repositories until the upgrade can be applied.
Fix this in GitLab
Scoped from the published advisory
- Consultation2.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,536.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-13262 — 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-2020-13262 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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
- No spam, self-promotion, credentials, or personal data