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.
Affected products
github: enterprise server
References7
- docs.github.com/en/[email protected]/admin/release-notes#3… Release NotesVendor Advisory
- docs.github.com/en/[email protected]/admin/release-notes#3… Release NotesVendor Advisory
- docs.github.com/en/[email protected]/admin/release-notes#3… Release NotesVendor Advisory
- docs.github.com/en/[email protected]/admin/release-notes#3… Release NotesVendor Advisory
- docs.github.com/en/[email protected]/admin/release-notes#3… Release NotesVendor Advisory
- docs.github.com/en/[email protected]/admin/release-notes#3… Release NotesVendor Advisory
- docs.github.com/en/[email protected]/admin/release-notes#3… Release NotesVendor Advisory
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - CVSS 4.0
-
7.5
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 37 · as of 13 November 2026
- CWE
- CWE-185
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