GitLabApplication
CVE-2026-1090
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 · uneditedGitLab has remediated an issue in GitLab CE/EE affecting all versions from 10.6 before 18.7.6, 18.8 before 18.8.6, and 18.9 before 18.9.2 that could have allowed an authenticated user, when the `markdown_placeholders` feature flag was enabled, to inject JavaScript in a browser due to improper sanitization of placeholder content in markdown processing.
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 has a stored XSS vulnerability in markdown processing where improper sanitization of placeholder content allowed authenticated users to inject JavaScript when the `markdown_placeholders` feature flag was enabled. The vulnerability was present in GitLab CE/EE versions 10.6 through 18.7.5, 18.8.0-18.8.5, and 18.9.0-18.9.1.
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
>= 10.6.0, < 18.7.6>= 18.8.0, < 18.8.6>= 18.9.0, < 18.9.2CVSS 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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Check GitLab installation versionRun `gitlab-rake gitlab:env:info` or check `/opt/gitlab/version` or view the version in the GitLab Admin Area under 'Health Check'Affected if Version falls within 10.6.0-18.7.5, 18.8.0-18.8.5, or 18.9.0-18.9.1
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Verify markdown_placeholders feature flag statusAccess GitLab Rails console (`gitlab-rails console`) and run `Feature.enabled?(:markdown_placeholders)` or check in Admin Area under 'Feature Flags'Affected if Feature flag returns `true` or is listed as enabled
A user is affected if their GitLab version is within the vulnerable range AND the markdown_placeholders feature flag is enabled.
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.
dbcve · scoped18.7.618.8.618.9.2
Upgrade to GitLab 18.7.6, 18.8.6, or 18.9.2 or later; alternatively, verify the `markdown_placeholders` feature flag is disabled until patching can be completed.
18.9.2 (or 18.8.6 or 18.7.6 depending on your current version branch)
- Identify the current GitLab version by checking /opt/gitlab/version or using `gitlab-rake gitlab:env:info`
- Determine which vulnerable version range your current installation falls into (>= 10.6.0 and < 18.7.6, >= 18.8.0 and < 18.8.6, or >= 18.9.0 and < 18.9.2)
- Create a full backup of the GitLab instance before proceeding with the upgrade
- Upgrade GitLab to version 18.9.2 (the latest fixed release for the 18.9 branch), or to 18.8.6 if on the 18.8 branch, or to 18.7.6 if on an earlier branch
- After upgrade, verify the installation by checking the version with `gitlab-rake gitlab:env:info`
- Confirm the `markdown_placeholders` feature flag is appropriately configured or has been disabled if not needed
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in GitLab
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-1090 — 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-2026-1090 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
- No spam, self-promotion, credentials, or personal data