{"cve":"CVE-2026-4296","nvd":{"published":"2026-04-21T23:16:21.807","modified":"2026-10-26T22:10:00.163","status":"Analyzed","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_v4":{"vector":"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","score":7.5},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-185"],"references":["https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.26","https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.21","https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.17","https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.14","https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.8"],"products":["github:enterprise_server"],"source":"nvd","synced_at":"2026-10-26T22:26:44.656832877+00:00"},"epss":{"cve":"CVE-2026-4296","score":0.00426,"percentile":0.36578,"date":"2026-10-26"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}