Advisory severityHigh8.5Red Hat Linux

High [CVE-2026-49332] underscore header smuggling enables identity impersonation on WSGI/PHP upstreams

This high-severity Red Hat Linux advisory covers CVE-2026-49332 affecting Red Hat OpenShift Container Platform 4.12, Red Hat OpenShift Container Platform 4.13, Red Hat OpenShift Container Platform 4.14.

Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.

CVE-2026-49332 Source published Jul 28, 2026Source updated Jul 28, 2026

VulniPulse record published Jul 28, 2026Record updated Aug 18, 2026

CVE-2026-49332

Affected products & platforms

Red Hat LinuxUnclassified

Open source advisory

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Summary

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. Red Hat severity: Important — CVSS 8.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N).

Weakness: CWE-436.

Affected Red Hat products: Red Hat OpenShift Container Platform 4.12; Red Hat OpenShift Container Platform 4.13; Red Hat OpenShift Container Platform 4.14; Red Hat OpenShift Container Platform 4.15; Red Hat OpenShift Container Platform 4.16; Red Hat OpenShift Container Platform 4.17; Red Hat OpenShift Container Platform 4.18; Red Hat OpenShift Container Platform 4.19; Red Hat OpenShift Container Platform 4.20; Red Hat OpenShift Container Platform 4.21; Red Hat OpenShift Container Platform 4.22.

Red Hat fixing advisory: RHSA-2026:54206, RHSA-2026:54188, RHSA-2026:50681, RHSA-2026:56912, RHSA-2026:50758, RHSA-2026:60023, RHSA-2026:51013, RHSA-2026:51007, RHSA-2026:51022, RHSA-2026:51025, RHSA-2026:51038.

Affected versions

No affected-version range was extracted from the source record. The vendor advisory is authoritative. Check it before change work.

Official advisory · high-confidence parse· fetched 27 days ago·verify at source

Fixed versions

openshift4/ose-oauth-proxy:1786458704
openshift4/ose-oauth-proxy:1786477436
openshift4/ose-oauth-proxy:1785549818
openshift4/ose-oauth-proxy-rhel9:1787054100
openshift4/ose-oauth-proxy-rhel9:1785544039
openshift4/ose-oauth-proxy-rhel9:1787543313
openshift4/ose-oauth-proxy-rhel9:1785529735
openshift4/ose-oauth-proxy-rhel9:1785521728
openshift4/ose-oauth-proxy-rhel9:1785833742
openshift4/ose-oauth-proxy-rhel9:1785851359
openshift4/ose-oauth-proxy-rhel9:1785885351
RHSA-2026:54206
RHSA-2026:54188
RHSA-2026:50681
RHSA-2026:56912
RHSA-2026:50758
RHSA-2026:60023
RHSA-2026:51013
RHSA-2026:51007
RHSA-2026:51022
RHSA-2026:51025
RHSA-2026:51038

Official advisory · high-confidence parse· fetched 27 days ago·verify at source

Mitigation checklist

Recommended fix / mitigation

Upstream application hardening: validate X-Forwarded-User against the expected session identity. Reject requests where identity headers do not match the authenticated session.

Official advisory · high-confidence parse· fetched 27 days ago·verify at source

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Sources

Official and corroborating records used to build this advisory.

Red Hat Security Data APIofficial
Official vendor source used to discover this advisory; it remains the authority for affected products and remediation. Discovered from the machine-readable feed https://access.redhat.com/hydra/rest/securitydata/cve.json; this link opens the Red Hat Linux advisory index instead of the raw feed document.
Red Hat Linux
Official vendor advisoryofficial
Official advisory page fetched and parsed; accepted detail fields are attributed to this page.
Red Hat Linux
CVE.org CNA affected-product recordCVE.org
Structured CNA affected[] data independently confirmed the affected product scope; native advisory content remains authoritative.
CVE Program

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CVE-2026-49332NVD CVE.org MITRE

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High [CVE-2026-49332] underscore header smuggling enables identity impersonation on WSGI/PHP upstreams

Get an email when Red Hat Linux publishes the next one.

Summary

Affected versions

Mitigation checklist

More Red Hat Linux advisories

Monitor future Red Hat Linux CVEs from your phone.

Discussion(0)