Description
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.
References10
- access.redhat.com/errata/RHSA-2026:50681
- access.redhat.com/errata/RHSA-2026:50758
- access.redhat.com/errata/RHSA-2026:51007
- access.redhat.com/errata/RHSA-2026:51013
- access.redhat.com/errata/RHSA-2026:51022
- access.redhat.com/errata/RHSA-2026:51025
- access.redhat.com/errata/RHSA-2026:51038
- access.redhat.com/errata/RHSA-2026:54188
- access.redhat.com/errata/RHSA-2026:54206
- access.redhat.com/errata/RHSA-2026:56912
Metrics
- CVSS 3.1
-
8.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N - EPSS — exploit probability
- 1% percentile: 45 · as of 13 November 2026
- CWE
- CWE-436
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.