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GitLabApplication

CVE-2023-2198

HIGH · 7.5 CVSS v3.1 Published 2023-06-07
Fix available
A fix is available. Upgrade to 15.10.8 / 15.11.7 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
An issue has been discovered in GitLab CE/EE affecting all versions starting from 8.7 before 15.10.8, all versions starting from 15.11 before 15.11.7, all versions starting from 16.0 before 16.0.2. A Regular Expression Denial of Service was possible via sending crafted payloads to the preview_markdown endpoint.

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

A Regular Expression Denial of Service (ReDoS) vulnerability exists in GitLab CE/EE's preview_markdown endpoint across multiple affected version ranges. Attackers can send specially crafted payloads that cause the regex engine to consume excessive CPU resources, leading to service degradation or unavailability.

MitigationUpgrade GitLab to version 15.10.8, 15.11.7, 16.0.2 or later. There are no configuration-based workarounds; the vulnerability is in the regex processing logic and requires the vendor patch.

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:>= 8.7.0, < 15.10.8>= 15.11.0, < 15.11.7>= 16.0.0, < 16.0.2

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. Identify GitLab installation type and location
    Determine whether GitLab is self-hosted (on-premises) or GitLab.com (SaaS). Self-hosted instances can be identified by checking for /opt/gitlab directory, running 'gitlab-rake gitlab:env:info', or accessing the Admin area via the web UI at /admin. For GitLab.com, this is a SaaS offering.
    Affected if Self-hosted GitLab installations are within scope; GitLab.com users should check status.gitlab.com for announcements.
  2. Determine installed GitLab version
    Run 'gitlab-rake gitlab:env:info' on the GitLab server, access the Admin UI at /admin and navigate to Help > Version, or query the API endpoint /api/v4/version. For Docker installations, run 'docker exec <container> gitlab-rake gitlab:env:info'.
    Affected if The version falls within any of these ranges: >= 8.7.0 and < 15.10.8, OR >= 15.11.0 and < 15.11.7, OR >= 16.0.0 and < 16.0.2.
  3. Verify preview_markdown endpoint is accessible
    Confirm the GitLab instance has the preview_markdown API endpoint available. This endpoint typically exists at /api/v4/projects/:id/preview_markdown. Check if the API responds to authenticated requests by sending a POST request with a test markdown payload.
    Affected if The endpoint is reachable and responds to API requests, enabling the vulnerable regex processing path.
  4. Check for signs of ReDoS exploitation
    Review GitLab logs (/var/log/gitlab/gitlab-rails/production.log) for patterns of excessive CPU usage, slow response times, or timeout errors associated with preview_markdown requests. Look for repeated requests with complex markdown content.
    Affected if Logs show abnormal regex processing times, request timeouts, or high CPU consumption correlated with preview_markdown API calls.

A user is affected if their self-hosted GitLab version falls within the specified vulnerable ranges and the preview_markdown endpoint is accessible, enabling attackers to trigger excessive regex processing.

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 15.10.8 / 15.11.7 / 16.0.2 or later
Fixed in 15.10.815.11.716.0.2
Interim mitigation

Upgrade GitLab to version 15.10.8, 15.11.7, 16.0.2 or later. There are no configuration-based workarounds; the vulnerability is in the regex processing logic and requires the vendor patch.

Recommended fix High confidence

15.10.8, 15.11.7, or 16.0.2 (or latest stable release)

  1. Identify current GitLab version by running `sudo gitlab-rake gitlab:env:info` or checking the Admin Area > Settings
  2. Review the GitLab upgrade path documentation to determine the correct upgrade path from your current version
  3. Back up your GitLab instance data, including the database and repositories
  4. For minor version upgrades within the same major version (e.g., 15.10.x to 15.10.8), update via your package manager: `sudo apt-get update && sudo apt-get install gitlab-ce` or `sudo yum install gitlab-ce`
  5. Alternatively, upgrade to the latest stable release (recommended) which includes all security patches
  6. After upgrade, verify GitLab is running: `sudo gitlab-ctl status`
  7. Test the preview_markdown functionality to ensure it works correctly
  8. Monitor system resources to confirm ReDoS vulnerability is mitigated
Caveat Minor version upgrades typically have minimal breaking changes; however, review GitLab's release notes for any deprecation notices before upgrading across major versions

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in GitLab Scoped from the published advisory
  • Consultation3.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
20.0 hours of engineering $3,480
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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-2023-2198 in production — separate from our analysis above.

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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