CVE-2026-4296
Received
Received - Intake
OAuth Redirect URI Bypass in GitHub Enterprise Server Enables Account Takeover
Publication date: 2026-04-21
Last updated on: 2026-04-29
Assigner: GitHub, Inc. (Products Only)
Description
Description
An incorrect regular expression vulnerability was identified in GitHub Enterprise Server that allowed an attacker to bypass OAuth redirect URI validation. An attacker with knowledge of a first-party OAuth application's registered callback URL could craft a malicious authorization link that, when clicked by a victim, would redirect the OAuth authorization code to an attacker-controlled domain. This could allow the attacker to gain unauthorized access to the victim's account with the scopes granted to the OAuth application. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| github | enterprise_server | to 3.14.26 (exc) |
| github | enterprise_server | From 3.15.0 (inc) to 3.15.21 (exc) |
| github | enterprise_server | From 3.16.0 (inc) to 3.16.17 (exc) |
| github | enterprise_server | From 3.17.0 (inc) to 3.17.14 (exc) |
| github | enterprise_server | From 3.18.0 (inc) to 3.18.8 (exc) |
| github | enterprise_server | From 3.19.0 (inc) to 3.19.5 (exc) |
| github | enterprise_server | 3.20.0 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-185 | The product specifies a regular expression in a way that causes data to be improperly matched or compared. |
