GitLabApplication
CVE-2023-5226
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 has been discovered in GitLab affecting all versions before 16.4.3, all versions starting from 16.5 before 16.5.3, all versions starting from 16.6 before 16.6.1. Under certain circumstances, a malicious actor bypass prohibited branch checks using a specially crafted branch name to manipulate repository content in the UI.
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 contains a vulnerability where specially crafted branch names can bypass prohibited branch checks, allowing a malicious actor to manipulate repository content through the UI by circumventing branch protection mechanisms.
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
< 16.4.3>= 16.5.0, < 16.5.3= 16.6.0CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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 GitLab versionAccess the GitLab Admin area Dashboard or use the API endpoint /api/v4/version to retrieve the current version numberAffected if The installed version is less than 16.4.3, or between 16.5.0 and 16.5.3 inclusive, or exactly 16.6.0
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Confirm branch protection is configuredNavigate to repository Settings > Repository > Protected branches to verify if any branches have protection rules definedAffected if Protected branches are defined in the repository settings
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Audit existing branch names for anomaliesReview the branch list in the repository and check for branch names containing special characters, null bytes, or encoding variations that could bypass validationAffected if Any branches exist with unusual characters or encoding that may have circumvented prohibited branch name checks
Your environment is affected if GitLab version falls within the vulnerable range AND branch protection rules are in use, as specially crafted branch names could bypass those protections
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 · scoped16.4.316.5.3
Upgrade GitLab to version 16.4.3, 16.5.3, or 16.6.1 or later to patch the vulnerability. Review existing branch protections and monitor for any suspicious branch names in existing repositories.
GitLab 16.6.1 or later ( alternatively 16.5.3 or 16.4.3 )
- 1. Back up your GitLab instance data and configuration
- 2. Ensure you are currently running an affected version (< 16.4.3, >= 16.5.0 and < 16.5.3, or 16.6.0)
- 3. Plan maintenance window as upgrade may require downtime
- 4. For self-managed GitLab, stop the GitLab services before upgrade
- 5. Update to GitLab 16.6.1 or later (preferred) using your package manager or upgrade method
- 6. After upgrade, verify GitLab is functioning correctly
- 7. Confirm the version by checking Admin Area > Settings > General > GitLab version
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-2023-5226 — 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-2023-5226 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
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