Openshift/oauth-proxy: openshift/oauth-proxy: underscore header smuggling enables…
Priority LOW 37CWE-436Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00531 45th percentileScored 2026-11-07
Fix Fixed Red Hat: 11 advisories
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat OpenShift Container Platform 4.12 | — | 1786458704 | Patch available | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4.13 | — | 1786477436 | Patch available | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4.14 | — | 1785549818 | Patch available | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4.15 | — | 1787054100 | Patch available | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4.16 | — | 1785544039 | Patch available | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4.17 | — | 1787543313 | Patch available | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4.18 | — | 1785529735 | Patch available | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4.19 | — | 1785521728 | Patch available | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4.20 | — | 1785833742 | Patch available | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4.21 | — | 1785851359 | Patch available | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4.22 | — | 1785885351 | Patch available | CNA |
- Red Hat OpenShift Container Platform 4.12 VendorRed Hat Affected — Fixed in 1786458704 Patch available CNA
- Red Hat OpenShift Container Platform 4.13 VendorRed Hat Affected — Fixed in 1786477436 Patch available CNA
- Red Hat OpenShift Container Platform 4.14 VendorRed Hat Affected — Fixed in 1785549818 Patch available CNA
- Red Hat OpenShift Container Platform 4.15 VendorRed Hat Affected — Fixed in 1787054100 Patch available CNA
- Red Hat OpenShift Container Platform 4.16 VendorRed Hat Affected — Fixed in 1785544039 Patch available CNA
- Red Hat OpenShift Container Platform 4.17 VendorRed Hat Affected — Fixed in 1787543313 Patch available CNA
- Red Hat OpenShift Container Platform 4.18 VendorRed Hat Affected — Fixed in 1785529735 Patch available CNA
- Red Hat OpenShift Container Platform 4.19 VendorRed Hat Affected — Fixed in 1785521728 Patch available CNA
- Red Hat OpenShift Container Platform 4.20 VendorRed Hat Affected — Fixed in 1785833742 Patch available CNA
- Red Hat OpenShift Container Platform 4.21 VendorRed Hat Affected — Fixed in 1785851359 Patch available CNA
- Red Hat OpenShift Container Platform 4.22 VendorRed Hat Affected — Fixed in 1785885351 Patch available CNA
CPE names CNA · 11
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/a:redhat:openshift:4.12::el9 | 4.12 | — | Red Hat |
| cpe:/a:redhat:openshift:4.13::el9 | 4.13 | — | Red Hat |
| cpe:/a:redhat:openshift:4.14::el9 | 4.14 | — | Red Hat |
| cpe:/a:redhat:openshift:4.15::el9 | 4.15 | — | Red Hat |
| cpe:/a:redhat:openshift:4.16::el9 | 4.16 | — | Red Hat |
| cpe:/a:redhat:openshift:4.17::el9 | 4.17 | — | Red Hat |
| cpe:/a:redhat:openshift:4.18::el9 | 4.18 | — | Red Hat |
| cpe:/a:redhat:openshift:4.19::el9 | 4.19 | — | Red Hat |
| cpe:/a:redhat:openshift:4.20::el9 | 4.20 | — | Red Hat |
| cpe:/a:redhat:openshift:4.21::el9 | 4.21 | — | Red Hat |
- cpe:/a:redhat:openshift:4.12::el9 Versions 4.12 — ·Red Hat
- cpe:/a:redhat:openshift:4.13::el9 Versions 4.13 — ·Red Hat
- cpe:/a:redhat:openshift:4.14::el9 Versions 4.14 — ·Red Hat
- cpe:/a:redhat:openshift:4.15::el9 Versions 4.15 — ·Red Hat
- cpe:/a:redhat:openshift:4.16::el9 Versions 4.16 — ·Red Hat
- cpe:/a:redhat:openshift:4.17::el9 Versions 4.17 — ·Red Hat
- cpe:/a:redhat:openshift:4.18::el9 Versions 4.18 — ·Red Hat
- cpe:/a:redhat:openshift:4.19::el9 Versions 4.19 — ·Red Hat
- cpe:/a:redhat:openshift:4.20::el9 Versions 4.20 — ·Red Hat
- cpe:/a:redhat:openshift:4.21::el9 Versions 4.21 — ·Red Hat
Remediation
Red Hat 11 advisories
- RHSA-2026:60023 Released 2026-09-03 · Red Hat rating ImportantOpenShift Container Platform 4.17.57 bug fix and security update
- Red Hat OpenShift Container Platform 4.17 registry.redhat.io/openshift4/egress-router-cni-rhel9, registry.redhat.io/openshift4/frr-rhel9, registry.redhat.io/openshift4/ose-apiserver-network-proxy-rhel9 +20
- RHSA-2026:56912 Released 2026-08-26 · Red Hat rating CriticalOpenShift Container Platform 4.15.68 bug fix and security update
- Red Hat OpenShift Container Platform 4.15 registry.redhat.io/openshift4/kubevirt-csi-driver-rhel8, registry.redhat.io/openshift4/ose-apiserver-network-proxy-rhel9, registry.redhat.io/openshift4/ose-console +5
- RHSA-2026:54188 Released 2026-08-20 · Red Hat rating ImportantOpenShift Container Platform 4.13.70 bug fix and security update
- Red Hat OpenShift Container Platform 4.13 registry.redhat.io/openshift4/ose-console, registry.redhat.io/openshift4/ose-oauth-proxy
Show 8 more Red Hat advisories
- RHSA-2026:54206 Released 2026-08-20 · Red Hat rating ImportantOpenShift Container Platform 4.12.96 bug fix and security update
- Red Hat OpenShift Container Platform 4.12 registry.redhat.io/openshift4/ose-console, registry.redhat.io/openshift4/ose-oauth-proxy
- RHSA-2026:50758 Released 2026-08-12 · Red Hat rating CriticalOpenShift Container Platform 4.16.68 bug fix and security update
- Red Hat OpenShift Container Platform 4.16 registry.redhat.io/openshift4/kubevirt-csi-driver-rhel9, registry.redhat.io/openshift4/ose-hypershift-rhel9, registry.redhat.io/openshift4/ose-monitoring-plugin-rhel9 +2
- RHSA-2026:50681 Released 2026-08-12 · Red Hat rating ImportantOpenShift Container Platform 4.14.71 bug fix and security update
- Red Hat OpenShift Container Platform 4.14 registry.redhat.io/openshift4/ose-console, registry.redhat.io/openshift4/ose-oauth-proxy
- RHSA-2026:51007 Released 2026-08-12 · Red Hat rating ImportantOpenShift Container Platform 4.19.42 bug fix and security update
- Red Hat OpenShift Container Platform 4.19 registry.redhat.io/openshift4/ose-monitoring-plugin-rhel9, registry.redhat.io/openshift4/ose-oauth-proxy-rhel9, registry.redhat.io/openshift4/ose-ovn-kubernetes-rhel9
- RHSA-2026:51013 Released 2026-08-12 · Red Hat rating ImportantOpenShift Container Platform 4.18.52 bug fix and security update
- Red Hat OpenShift Container Platform 4.18 registry.redhat.io/openshift4/ose-oauth-proxy-rhel9, registry.redhat.io/openshift4/ose-ovn-kubernetes-rhel9
- RHSA-2026:51038 Released 2026-08-11 · Red Hat rating ImportantOpenShift Container Platform 4.22.9 bug fix and security update
- Red Hat OpenShift Container Platform 4.22 registry.redhat.io/openshift4/ose-agent-installer-ui-rhel9, registry.redhat.io/openshift4/ose-console-rhel9, registry.redhat.io/openshift4/ose-hyperkube-rhel9 +4
- RHSA-2026:51022 Released 2026-08-11 · Red Hat rating ImportantOpenShift Container Platform 4.20.33 bug fix and security update
- Red Hat OpenShift Container Platform 4.20 registry.redhat.io/openshift4/ose-oauth-proxy-rhel9, registry.redhat.io/openshift4/ose-ovn-kubernetes-rhel9
- RHSA-2026:51025 Released 2026-08-11 · Red Hat rating ImportantOpenShift Container Platform 4.21.28 bug fix and security update
- Red Hat OpenShift Container Platform 4.21 registry.redhat.io/openshift4/ose-oauth-proxy-rhel9
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat OpenShift Container Platform 4.12 | Fixed | RHSA-2026:54206 |
| Red Hat OpenShift Container Platform 4.13 | Fixed | RHSA-2026:54188 |
| Red Hat OpenShift Container Platform 4.14 | Fixed | RHSA-2026:50681 |
| Red Hat OpenShift Container Platform 4.15 | Fixed | RHSA-2026:56912 |
| Red Hat OpenShift Container Platform 4.16 | Fixed | RHSA-2026:50758 |
| Red Hat OpenShift Container Platform 4.17 | Fixed | RHSA-2026:60023 |
| Red Hat OpenShift Container Platform 4.18 | Fixed | RHSA-2026:51013 |
| Red Hat OpenShift Container Platform 4.19 | Fixed | RHSA-2026:51007 |
| Red Hat OpenShift Container Platform 4.20 | Fixed | RHSA-2026:51022 |
| Red Hat OpenShift Container Platform 4.21 | Fixed | RHSA-2026:51025 |
| Red Hat OpenShift Container Platform 4.22 | Fixed | RHSA-2026:51038 |
Not affected: 11 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
Timeline
- 2026-10-02 Threatist record created from CVE-2026-49332
- 2026-10-03 Alias added: GHSA-f2m2-cc3f-h4j2
References
More Red Hat vulnerabilities
- TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
- TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
- TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
- TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
- TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-49332 · CVE Program
- CVE-2026-49332 · NVD
- FIRST EPSS
- GHSA-f2m2-cc3f-h4j2 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-49332 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences