Vulnerability record · CVE-2026-4296 · published 21 April 2026
CVE-2026-4296: Github enterprise server vulnerability
Github · Enterprise Server
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.
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: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:
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://docs.github.com/en/[email protected]/admin/release-notes#3.14.26 | Release NotesVendor Advisory |
| https://docs.github.com/en/[email protected]/admin/release-notes#3.15.21 | Release NotesVendor Advisory |
| https://docs.github.com/en/[email protected]/admin/release-notes#3.16.17 | Release NotesVendor Advisory |
| https://docs.github.com/en/[email protected]/admin/release-notes#3.17.14 | Release NotesVendor Advisory |
| https://docs.github.com/en/[email protected]/admin/release-notes#3.18.8 | Release NotesVendor Advisory |
| https://docs.github.com/en/[email protected]/admin/release-notes#3.19.5 | Release NotesVendor Advisory |
| https://docs.github.com/en/[email protected]/admin/release-notes#3.20.1 | Release NotesVendor Advisory |
Track CVE-2026-4296 inside VULONE
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Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-4296), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.
