CVE-2026-4296

HIGH EPSS 23.4%
Published Apr 21, 20262mo ago · Modified Jun 17, 20261w ago
7.5 CVSS 4.0
High
Find Similar
Published Apr 21, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

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 Details

Base Score
7.5
Exploitability
Impact
Vector string
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
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction P
Scope X

Threat Intelligence

EPSS Exploit Probability
23.4% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-185

Affected Products 7

VendorProductVersionRange
githubenterprise_server* <3.14.26
githubenterprise_server*≥3.15.0  –  <3.15.21
githubenterprise_server*≥3.16.0  –  <3.16.17
githubenterprise_server*≥3.17.0  –  <3.17.14
githubenterprise_server*≥3.18.0  –  <3.18.8
githubenterprise_server*≥3.19.0  –  <3.19.5
githubenterprise_server3.20.0any

References 7

  • docs.github.com https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.26
    Release NotesVendor Advisory
  • docs.github.com https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.21
    Release NotesVendor Advisory
  • docs.github.com https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.17
    Release NotesVendor Advisory
  • docs.github.com https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.14
    Release NotesVendor Advisory
  • docs.github.com https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.8
    Release NotesVendor Advisory
  • docs.github.com https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.5
    Release NotesVendor Advisory
  • docs.github.com https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.1
    Release NotesVendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.