CVE-2026-4296
HIGHDescription
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 v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Exploit Intelligence
Low risk: more likely to be exploited than 23% of all known CVEs.
References
- https://docs.github.com/en/[email protected]/admin/release-notes#3.14.26
- https://docs.github.com/en/[email protected]/admin/release-notes#3.15.21
- https://docs.github.com/en/[email protected]/admin/release-notes#3.16.17
- https://docs.github.com/en/[email protected]/admin/release-notes#3.17.14
- https://docs.github.com/en/[email protected]/admin/release-notes#3.18.8
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.5
- https://docs.github.com/en/[email protected]/admin/release-notes#3.20.1
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-29.