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Enterprise ServerApplication · GitHub

CVE-2026-10585

MEDIUM · 5.4 CVSS v3.1 Published 2026-06-30
Fix available
A fix is available. Upgrade to 3.16.20 / 3.17.17 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable 7 weeks old

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
A stored cross-site scripting vulnerability was identified in GitHub Enterprise Server that allowed an authenticated attacker to execute arbitrary JavaScript in another user's browser by injecting a crafted payload into the title of a Discussion in the Q&A category. The AnsweredQuestionStructuredDataComponent did not escape user-controlled Discussion titles before embedding them in a <script type="application/ld+json"> block, allowing the title to break out of the script context. The injection was escalated to a full cross-site scripting attack on GitHub Enterprise Server by leveraging JSONP callback support in the REST API to bypass the Content Security Policy. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.4, 3.19.8, 3.18.11, 3.17.17, 3.16.20. 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 confidence

A stored XSS vulnerability in GitHub Enterprise Server allowed authenticated attackers to inject malicious JavaScript through Discussion titles in the Q&A category. The AnsweredQuestionStructuredDataComponent failed to escape user-controlled Discussion titles before embedding them in a <script type='application/ld+json'> block, enabling the title to break out of the script context. Attackers escalated this to full XSS by using JSONP callback support in the REST API to bypass Content Security Policy protections.

MitigationUpgrade GitHub Enterprise Server to version 3.20.4, 3.19.8, 3.18.11, 3.17.17, or 3.16.20 or later to patch this vulnerability. Organizations unable to upgrade immediately should restrict Discussion creation privileges to trusted users.

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
Affected:< 3.16.20>= 3.17.0, < 3.17.17>= 3.18.0, < 3.18.11>= 3.19.0, < 3.19.8>= 3.20.0, < 3.20.4

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
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 checks

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

  1. Determine installed GitHub Enterprise Server version
    Run 'ghe-version' command from the management shell, or check the GitHub Enterprise Admin Settings > About page in the web UI
    Affected if Version falls into any of the affected ranges: < 3.16.20; >= 3.17.0 and < 3.17.17; >= 3.18.0 and < 3.18.11; >= 3.19.0 and < 3.19.8; >= 3.20.0 and < 3.20.4
  2. Verify Discussions feature is enabled
    Check Site Admin settings under 'Discussion' settings or review organization/repository settings to confirm the Discussions feature is turned on
    Affected if Discussions are enabled - the vulnerability only applies when the feature is active
  3. Identify Q&A category usage in Discussions
    Navigate to Discussions in any organization/repository and inspect whether the Q&A category exists or has been used. Check via API: GET /repos/{owner}/{repo}/discussions/categories
    Affected if Q&A category exists or has been used - the flaw specifically targets this category
  4. Search for suspicious discussion titles in Q&A category
    Use GitHub search or API to query discussion titles in Q&A category for patterns like '<script', 'javascript:', 'onerror=', 'onload=', or unexpected JSON-LD structures. API: GET /repos/{owner}/{repo}/discussions?category=Q&A
    Affected if Any discussion titles contain unescaped HTML, script tags, or JSONP callback patterns (e.g., ?callback=) - indicates active exploitation

Your environment is affected if you run a vulnerable GitHub Enterprise Server version AND have Discussions with the Q&A category enabled, particularly if suspicious script-containing titles are found in Q&A discussions.

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 3.16.20 / 3.17.17 / 3.18.11 or later
Fixed in 3.16.203.17.173.18.11
Interim mitigation

Upgrade GitHub Enterprise Server to version 3.20.4, 3.19.8, 3.18.11, 3.17.17, or 3.16.20 or later to patch this vulnerability. Organizations unable to upgrade immediately should restrict Discussion creation privileges to trusted users.

Recommended fix High confidence

Upgrade to version 3.16.20, 3.17.17, 3.18.11, 3.19.8, or 3.20.4 (or later) depending on your current branch; recommended: 3.20.4 or latest stable release

  1. 1. Identify the currently installed GitHub Enterprise Server version by checking the Management Console or running 'ghe-version' command
  2. 2. Based on the current version, determine the minimum required upgrade path: if < 3.16.20 upgrade to 3.16.20+, if 3.17.0-3.16.x upgrade to 3.17.17+, if 3.18.0-3.18.10 upgrade to 3.18.11+, if 3.19.0-3.19.7 upgrade to 3.19.8+
  3. 3. Review the GitHub Enterprise Server upgrade prerequisites and backup requirements at docs.github.com
  4. 4. Perform a backup of the GitHub Enterprise Server instance before upgrading
  5. 5. Download the appropriate GitHub Enterprise Server upgrade package from enterprise.github.com
  6. 6. Follow the standard upgrade procedure using the Management Console or command-line utilities
  7. 7. After upgrade, verify the new version is running using 'ghe-version'
  8. 8. Test that discussions in the Q&A category function properly and that the stored XSS vulnerability is no longer present
Caveat Review release notes for your target version for any breaking changes; major version jumps may require additional migration steps

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

Fix this in Enterprise Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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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-2026-10585 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
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  • Version or environment caveats, and links to real fixes
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