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GitLabApplication

CVE-2026-3988

HIGH · 7.5 CVSS v3.1 Published 2026-03-25
Fix available
A fix is available. Upgrade to 18.8.7 / 18.9.3 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.5 before 18.8.7, 18.9 before 18.9.3, and 18.10 before 18.10.1 that could have allowed an unauthenticated user to cause a denial of service by making the GitLab instance unresponsive due to improper input validation in GraphQL request 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 confidence

An unauthenticated attacker can send specially crafted GraphQL requests with improper input validation that causes the GitLab instance to become unresponsive, resulting in denial of service. The vulnerability affects specific versions of GitLab CE/EE (18.5 before 18.8.7, 18.9 before 18.9.3, and 18.10 before 18.10.1).

MitigationUpgrade GitLab to version 18.8.7, 18.9.3, 18.10.1 or later to patch the improper input validation vulnerability in GraphQL processing.

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
Affected:>= 18.5.0, < 18.8.7>= 18.9.0, < 18.9.3= 18.10.0

CVSS 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
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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 checks

Work through these to decide whether this CVE applies to you.

  1. Check installed GitLab version
    Run `sudo gitlab-rake gitlab:env:info` or check the GitLab admin area under Help > Version to find the exact version number
    Affected if The displayed version is 18.5.0 through 18.8.6, 18.9.0 through 18.9.2, or exactly 18.10.0
  2. Confirm GraphQL endpoint is accessible
    Send a GET request to `https://your-gitlab-instance/-/graphql` or `/api/graphql` to verify the GraphQL endpoint is exposed
    Affected if The endpoint responds (GitLab instances with GraphQL enabled are vulnerable; it is enabled by default in CE/EE)
  3. Verify version falls within affected range
    Compare your installed version against the affected ranges: 18.5.0-18.8.6, 18.9.0-18.9.2, or 18.10.0
    Affected if Your version matches any of these ranges

You are affected if your GitLab version is 18.5.0-18.8.6, 18.9.0-18.9.2, or 18.10.0 and the GraphQL endpoint is accessible (default configuration).

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 18.8.7 / 18.9.3 or later
Fixed in 18.8.718.9.3
Interim mitigation

Upgrade GitLab to version 18.8.7, 18.9.3, 18.10.1 or later to patch the improper input validation vulnerability in GraphQL processing.

Recommended fix High confidence

Upgrade to GitLab 18.8.7, 18.9.3, or 18.10.1 (or later) depending on your current minor version branch

  1. Identify your current GitLab version using gitlab-rake gitlab:env:info
  2. Back up your GitLab instance database and repositories
  3. For Debian/Ubuntu: Run sudo apt-get update && sudo apt-get install gitlab-ce (or gitlab-ee) to upgrade to the latest available version in your current minor branch, or specify the exact version using apt-get install gitlab-ce=<version>
  4. For RHEL/CentOS: Run sudo yum install gitlab-ce (or gitlab-ee) to upgrade to the latest available version, or specify the exact version using yum install gitlab-ce-<version>
  5. After upgrade, run sudo gitlab-ctl reconfigure
  6. Verify the upgrade was successful using gitlab-rake gitlab:env:info and confirm the version is 18.8.7, 18.9.3, or 18.10.1 or later
Caveat Review GitLab release notes for any breaking changes between your current version and the target version before upgrading

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
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-3988 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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