CVE-2021-22863
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.00%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- EPSS
- 1.00% probability · 63th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-285
- Affected
- github/github
- Source
- product-cna@github.com
EPSS 1.0% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://docs.github.com/en/enterprise-server%402.20/admin/release-notes#2.20.24
- https://docs.github.com/en/enterprise-server%402.21/admin/release-notes#2.21.15
- https://docs.github.com/en/enterprise-server%402.22/admin/release-notes#2.22.7
- https://docs.github.com/en/enterprise-server%403.0/admin/release-notes#3.0.1
- https://docs.github.com/en/enterprise-server%402.20/admin/release-notes#2.20.24
- https://docs.github.com/en/enterprise-server%402.21/admin/release-notes#2.21.15
- https://docs.github.com/en/enterprise-server%402.22/admin/release-notes#2.22.7
- https://docs.github.com/en/enterprise-server%403.0/admin/release-notes#3.0.1
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.