OpenShift OAuth-Proxy Header Injection via Underscore-variant
CVE-2026-49332 Published on July 28, 2026
Openshift/oauth-proxy: openshift/oauth-proxy: underscore header smuggling enables identity impersonation on wsgi/php upstreams
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.
Vulnerability Analysis
CVE-2026-49332 is exploitable with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity, and no impact on availability.
Timeline
Reported to Red Hat.
Made public. 102 days later.
Weakness Type
Interpretation Conflict
Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state. This is generally found in proxies, firewalls, anti-virus software, and other intermediary devices that monitor, allow, deny, or modify traffic based on how the client or server is expected to behave.
Products Associated with CVE-2026-49332
Want to know whenever a new CVE is published for Red Hat Openshift? stack.watch will email you.
