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

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-49332",
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "dateUpdated": "2026-07-28T13:03:08.605Z",
    "dateReserved": "2026-05-29T13:28:56.553Z",
    "datePublished": "2026-07-28T12:18:26.112Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat",
        "dateUpdated": "2026-07-28T12:18:26.112Z"
      },
      "datePublic": "2026-07-28T12:00:00.000Z",
      "title": "Openshift/oauth-proxy: openshift/oauth-proxy: underscore header smuggling enables identity impersonation on wsgi/php upstreams",
      "descriptions": [
        {
          "lang": "en",
          "value": "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": [
        {
          "vendor": "Red Hat",
          "product": "Red Hat OpenShift Container Platform 4",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "openshift4/ose-oauth-proxy",
          "cpes": [
            "cpe:/a:redhat:openshift:4"
          ],
          "defaultStatus": "affected"
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat OpenShift Container Platform 4",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "openshift4/ose-oauth-proxy-rhel9",
          "cpes": [
            "cpe:/a:redhat:openshift:4"
          ],
          "defaultStatus": "affected"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "Interpretation Conflict",
              "cweId": "CWE-436",
              "type": "CWE"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://access.redhat.com/security/cve/CVE-2026-49332",
          "tags": [
            "vdb-entry",
            "x_refsource_REDHAT"
          ]
        },
        {
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2483253",
          "name": "RHBZ#2483253",
          "tags": [
            "issue-tracking",
            "x_refsource_REDHAT"
          ]
        }
      ],
      "metrics": [
        {},
        {
          "format": "CVSS",
          "cvssV3_1": {
            "version": "3.1",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N",
            "attackVector": "NETWORK",
            "attackComplexity": "LOW",
            "privilegesRequired": "LOW",
            "userInteraction": "NONE",
            "scope": "CHANGED",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "availabilityImpact": "NONE",
            "baseScore": 8.5,
            "baseSeverity": "HIGH"
          }
        }
      ],
      "workarounds": [
        {
          "lang": "en",
          "value": "Upstream application hardening: validate X-Forwarded-User against the expected session identity. Reject requests where identity headers do not match the authenticated session."
        }
      ],
      "timeline": [
        {
          "time": "2026-04-17T00:00:00.000Z",
          "lang": "en",
          "value": "Reported to Red Hat."
        },
        {
          "time": "2026-07-28T12:00:00.000Z",
          "lang": "en",
          "value": "Made public."
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "This issue was discovered by Jeremy Choi (Red Hat)."
        }
      ]
    },
    "adp": [
      {
        "providerMetadata": {
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP",
          "dateUpdated": "2026-07-28T13:03:08.605Z"
        },
        "title": "CISA ADP Vulnrichment",
        "metrics": [
          {}
        ]
      }
    ]
  }
}