CVE-2026-9132
mediumpriority · track · 26OT risk · elevatedEPSS 0.004 · 36 %ileDEEUNLUSEPSS · scored 2026-10-27
A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to read source code from private repositories they did not have access to. The Copilot pull request description diff summary endpoint accepted a cross-repository comparison range and rendered the resulting diff without verifying that the requesting user was authorized to view the target repository. Exploitation required an authenticated account on the instance with read access to at least one repository to use as the comparison base. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.17.17, 3.18.11, 3.19.8, and 3.20.4. This vulnerability was reported via the GitHub Bug Bounty program.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.3–6.5
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (20)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- NCSC-2026-0219Kwetsbaarheden verholpen in GitHub Enterprise ServerNL2026-07-03csaf · ncsc_nlNL
GitHub heeft meerdere kwetsbaarheden verholpen in GitHub Enterprise Server, specifiek in versies vóór 3.21 en 3.22.
- WID-SEC-W-2026-2164Microsoft GitHub Enterprise Server: Mehrere SchwachstellenDeutsch2026-06-30csaf · cert_bundDE
Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Microsoft GitHub Enterprise Server ausnutzen, um einen Cross-Site Scripting Angriff durchzuführen, Sicherheitsmaßnahmen zu umgehen und vertrauliche Informationen offenzulegen.
also known as (3)
Other names and identifiers for this entity.
sources
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references (12)
External citations — patches, advisories, analysis.
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.17-featurescnnvd
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.11-featurescnnvd
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.8-featurescnnvd
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.4-featurescnnvd
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.17-featuresenisa_euvd
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.11-featuresenisa_euvd
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.8-featuresenisa_euvd
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.4-featuresenisa_euvd
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