CVE-2026-9132
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.
Does this matter?
Lower severity and a low EPSS score (0.41%). Track it; it rarely justifies an emergency change on its own.
Description
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 4.0
- 6.0 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.41% probability · 35th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-862
- Affected
- github/enterprise server
- Source
- product-cna@github.com
References
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.17-featuresRelease Notes
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.11-featuresRelease Notes
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.8-featuresRelease Notes
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.4-featuresRelease Notes
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.