An improper access control vulnerability was identified in GitHub Enterprise Server that allowed authenticated users of the instance to gain write access to unauthorized repositories via specifically crafted pull requests and REST API requests. An attacker would need to be able to fork the targeted repository, a setting that is disabled by default for organization owned private repositories. Branch protections such as required pull request reviews or status checks would prevent unauthorized commits from being merged without further review or validation. This vulnerability affected all versions of GitHub Enterprise Server since 2.4.21 and was fixed in versions 2.20.24, 2.21.15, 2.22.7 and 3.0.1. This vulnerability was reported via the GitHub Bug Bounty program.

An improper access control vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user with the ability to fork a repository to disclose Actions secrets for the parent repository of the fork. This vulnerability existed due to a flaw that allowed the base reference of a pull request to be updated to point to an arbitrary SHA or another pull request outside of the fork repository. By establishing this incorrect reference in a PR, the restrictions that limit the Actions secrets sent a workflow from forks could be bypassed. This vulnerability affected GitHub Enterprise Server version 3.0.0, 3.0.0.rc2, and 3.0.0.rc1. This vulnerability was reported via the GitHub Bug Bounty program.

An improper access control vulnerability was identified in the GitHub Enterprise Server GraphQL API that allowed authenticated users of the instance to modify the maintainer collaboration permission of a pull request without proper authorization. By exploiting this vulnerability, an attacker would be able to gain access to head branches of pull requests opened on repositories of which they are a maintainer. Forking is disabled by default for organization owned private repositories and would prevent this vulnerability. Additionally, branch protections such as required pull request reviews or status checks would prevent unauthorized commits from being merged without further review or validation. This vulnerability affected all versions of GitHub Enterprise Server since 2.12.22 and was fixed in versions 2.20.24, 2.21.15, 2.22.7 and 3.0.1. This vulnerability was reported via the GitHub Bug Bounty program.

An improper access control vulnerability was identified in GitHub Enterprise Server that allowed authenticated users of the instance to determine the names of unauthorized private repositories given their numerical IDs. This vulnerability did not allow unauthorized access to any repository content besides the name. This vulnerability affected all versions of GitHub Enterprise Server prior to 2.22 and was fixed in versions 2.21.6, 2.20.15, and 2.19.21. This vulnerability was reported via the GitHub Bug Bounty program.

A remote code execution vulnerability was identified in GitHub Enterprise Server that could be exploited when building a GitHub Pages site. User-controlled configuration of the underlying parsers used by GitHub Pages were not sufficiently restricted and made it possible to execute commands on the GitHub Enterprise Server instance. To exploit this vulnerability, an attacker would need permission to create and build a GitHub Pages site on the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 2.22 and was fixed in 2.21.6, 2.20.15, and 2.19.21. The underlying issues contributing to this vulnerability were identified both internally and through the GitHub Security Bug Bounty program.

Jenkins GitHub Coverage Reporter Plugin 1.8 and earlier stores secrets unencrypted in its global configuration file on the Jenkins master where they can be viewed by users with access to the master file system or read permissions on the system configuration.

The table extension in GitHub Flavored Markdown before version 0.29.0.gfm.1 takes O(n * n) time to parse certain inputs. An attacker could craft a markdown table which would take an unreasonably long time to process, causing a denial of service. This issue does not affect the upstream cmark project. The issue has been fixed in version 0.29.0.gfm.1.

An improper access control vulnerability was identified in the GitHub Enterprise Server API that allowed an organization member to escalate permissions and gain access to unauthorized repositories within an organization. This vulnerability affected all versions of GitHub Enterprise Server prior to 2.21 and was fixed in 2.20.9, 2.19.15, and 2.18.20. This vulnerability was reported via the GitHub Bug Bounty program.

A missing permission check in Jenkins Pipeline GitHub Notify Step Plugin 1.0.4 and earlier allows attackers with Overall/Read permission to connect to an attacker-specified URL using attacker-specified credentials IDs obtained through another method, capturing credentials stored in Jenkins.

A cross-site request forgery vulnerability in Jenkins Pipeline GitHub Notify Step Plugin 1.0.4 and earlier allows attackers to connect to an attacker-specified URL using attacker-specified credentials IDs obtained through another method, capturing credentials stored in Jenkins.