CVE-2026-4296
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| github | enterprise_server | {"endExcluding":"3.14.26"} | 3.14.26 |
| github | enterprise_server | 3.20.0 | |
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
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.5
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.1
CWEs
CWE-185
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.