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Vulnerability · Published Jul 28, 2026 · Assigned by redhat

CVE-2026-49332Openshift/oauth-proxy: openshift/oauth-proxy: underscore header smuggling enables identity impersonation on wsgi/php upstreams

High 8.5

In plain English

A high-severity security flaw in Red Hat OpenShift Container Platform 4.12 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities).

Severity (CVSS 3.1)8.5High
Exploit odds (30 days)0.5%top 54.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat OpenShift Container Platform 4.12 see references
Red Hat Red Hat OpenShift Container Platform 4.13 see references
Red Hat Red Hat OpenShift Container Platform 4.14 see references
Red Hat Red Hat OpenShift Container Platform 4.15 see references
Red Hat Red Hat OpenShift Container Platform 4.16 see references
Red Hat Red Hat OpenShift Container Platform 4.17 see references
Red Hat Red Hat OpenShift Container Platform 4.18 see references
Red Hat Red Hat OpenShift Container Platform 4.19 see references
Red Hat Red Hat OpenShift Container Platform 4.20 see references
Red Hat Red Hat OpenShift Container Platform 4.21 see references
Red Hat Red Hat OpenShift Container Platform 4.22 see references

Weakness: CWE-436 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

References