Enterprise ServerApplication · GitHub
CVE-2023-23763
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 authorization/sensitive information disclosure vulnerability was identified in GitHub Enterprise Server that allowed a fork to retain read access to an upstream repository after its visibility was changed to private. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.10.0 and was fixed in versions 3.9.4, 3.8.9, 3.7.16 and 3.6.18. This vulnerability was reported via the GitHub Bug Bounty program.
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 confidenceAn authorization bypass vulnerability in GitHub Enterprise Server allowed forks to retain read access to upstream repositories after the upstream visibility was changed to private. This means private repositories could have their content inadvertently exposed to users who forked them when they were public.
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
Enterprise ServerApplication
>= 3.6.0, < 3.6.18>= 3.7.0, < 3.7.16>= 3.8.0, < 3.8.9>= 3.9.0, < 3.9.4CVSS 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
- Low
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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 GitHub Enterprise Server versionAccess the GitHub Enterprise Server management console or run 'ghe-version' from the administrative shell to retrieve the installed version number.Affected if The installed version falls within any of these ranges: 3.6.0 to 3.6.17, 3.7.0 to 3.7.15, 3.8.0 to 3.8.8, or 3.9.0 to 3.9.3.
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Identify fork relationships in the instanceUse the GitHub Enterprise administrative API or audit log to enumerate all fork relationships. Look for repositories with 'fork' attribute set to true and query their parent (upstream) repositories.Affected if Any fork relationships exist where the fork was created when the upstream was public.
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Check for upstream repositories changed to privateReview repository visibility change events in the audit log, filtering for changes from 'public' to 'private'. Alternatively, query all private repositories and examine their audit history for prior visibility states.Affected if Any repository was changed from public to private visibility after having forks.
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Verify fork access to private upstream repositoriesTest whether forked repositories still have read access to their upstream repositories when the upstream is now private. This can be done by attempting to view content from the fork that would be sourced from the private upstream, or by checking permission models via API.Affected if Forks can still read content from their upstream repositories even after the upstream was changed to private.
You are affected if your GitHub Enterprise Server version is in the vulnerable range AND forks exist that were created when upstream repositories were public but those upstreams were subsequently changed to private while the forks retained access.
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 · scoped3.6.183.7.163.8.9
Upgrade GitHub Enterprise Server to version 3.9.4, 3.8.9, 3.7.16, 3.6.18, or 3.10.0 and later. Additionally, audit existing fork relationships to identify and revoke any unauthorized access that may have occurred prior to the upgrade.
Upgrade to version 3.6.18, 3.7.16, 3.8.9, or 3.9.4 (or to 3.10.0+ if available)
- 1. Back up your GitHub Enterprise Server data and configuration before starting the upgrade
- 2. Review the release notes for your target version (3.6.18, 3.7.16, 3.8.9, or 3.9.4) to understand changes and requirements
- 3. Download the appropriate GitHub Enterprise Server upgrade package from github.com/enterprise
- 4. Upload the upgrade package to your GitHub Enterprise Server instance
- 5. Navigate to the management console or use the command-line utility to initiate the upgrade
- 6. Monitor the upgrade process for any errors or warnings
- 7. Verify the upgrade was successful by checking the version in the management console
- 8. Test that the vulnerability is resolved by verifying forks cannot retain read access to upstream repositories after visibility changes to private
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Enterprise Server
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 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 $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-23763 — 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-2023-23763 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
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