CVE-2026-49332
Openshift/oauth-proxy: openshift/oauth-proxy: underscore header smuggling enables identity impersonation on wsgi/php upstreams
CVSS Score
8.5
EPSS Score
0.3%
EPSS Percentile
21th
A flaw was found in openshift/oauth-proxy. The proxy sets authenticated identity headers using only dash-variant keys (X-Forwarded-User) but does not strip underscore-variant keys (X_Forwarded_User) from incoming requests. WSGI and PHP frameworks normalize both variants to the same variable, allowing an authenticated low-privilege user to smuggle a forged identity that may override the legitimate authenticated identity in the upstream application.
| CWE | CWE-436 |
| Vendor | red hat |
| Product | red hat openshift container platform 4.14 |
| Published | Jul 28, 2026 |
| Last Updated | Aug 19, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
None
Affected Versions
Red Hat / Red Hat OpenShift Container Platform 4.14
All versions affected Red Hat / Red Hat OpenShift Container Platform 4.16
All versions affected Red Hat / Red Hat OpenShift Container Platform 4.18
All versions affected Red Hat / Red Hat OpenShift Container Platform 4.19
All versions affected Red Hat / Red Hat OpenShift Container Platform 4.20
All versions affected Red Hat / Red Hat OpenShift Container Platform 4.21
All versions affected Red Hat / Red Hat OpenShift Container Platform 4.22
All versions affected References
access.redhat.com: https://access.redhat.com/errata/RHSA-2026:50681 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:50758 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:51007 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:51013 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:51022 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:51025 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:51038 access.redhat.com: https://access.redhat.com/security/cve/CVE-2026-49332 bugzilla.redhat.com: https://bugzilla.redhat.com/show_bug.cgi?id=2483253
Credits
This issue was discovered by Jeremy Choi (Red Hat).