CVE-2021-22866 | UI misrepresentation of granted permissions in GitHub Enterprise Server leading to unauthorized access to user resources

A UI misrepresentation vulnerability was identified in GitHub Enterprise Server that allowed more permissions to be granted during a GitHub App's user-authorization web flow than was displayed to the user during approval. 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. All permissions being granted would properly be shown during the first authorization, but in certain circumstances, if the user revisits the authorization flow after the GitHub App has configured additional user-level permissions, those additional permissions may not be shown, leading to more permissions being granted than the user potentially intended. This vulnerability affected GitHub Enterprise Server 3.0.x prior to 3.0.7 and 2.22.x prior to 2.22.13. It was fixed in versions 3.0.7 and 2.22.13. This vulnerability was reported via the GitHub Bug Bounty program.

Published: 2021-05-14 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-22866 is rated Moderate Risk (56.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.04%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-22866

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.20% 1.04% +0.84%
2 2025-03-30 0.40% 0.20% -0.19%
3 2025-03-29 — 0.40% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-22866

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2021-22866

Affected software / configurations for CVE-2021-22866

Vendor Product Version Raw CPE
github enterprise_server >= 2.20.0, < 2.22.13 cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
github enterprise_server >= 3.0.0, < 3.0.7 cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*

References for CVE-2021-22866

cvelogic Threat Intelligence