CVE-2021-22865: An improper access control vulnerability was identified in GitHub Enterprise Server that allowed access tokens generated from a GitHub App's web authe...

Description

An improper access control vulnerability was identified in GitHub Enterprise Server that allowed access tokens generated from a GitHub App's web authentication flow to read private repository metadata via the REST API without having been granted the appropriate permissions. To exploit this vulnerability, an attacker would need to create a GitHub App on the instance and have a user authorize the application through the web authentication flow. The private repository metadata returned would be limited to repositories owned by the user the token identifies. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.0.4 and was fixed in versions 3.0.4, 2.22.10, 2.21.18. This vulnerability was reported via the GitHub Bug Bounty program.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS Probability

1.32%

67.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-285

Affected Software

Vendor	Product	Versions
Github	Enterprise Server	< 2.21.18
Github	Enterprise Server	>= 2.22.0, < 2.22.10
Github	Enterprise Server	>= 3.0.0, < 3.0.4

References

Timeline

Published: Apr 2, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-22865?

An improper access control vulnerability was identified in GitHub Enterprise Server that allowed access tokens generated from a GitHub App's web authentication flow to read private repository metadata via the REST API without having been granted the appropriate permissions. To exploit this vulnerability, an attacker would need to create a GitHub App on the instance and have a user authorize the application through the web authentication flow. The private repository metadata returned would be limited to repositories owned by the user the token identifies. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.0.4 and was fixed in versions 3.0.4, 2.22.10, 2.21.18. This vulnerability was reported via the GitHub Bug Bounty program.

How severe is CVE-2021-22865?

CVE-2021-22865 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.32% probability of exploitation in the next 30 days.

How do I fix CVE-2021-22865?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.