CVE-2026-18217
A flaw was found in the SAML protocol implementation of Keycloak, an open-source identity and access management solution. The issue occurs when Keycloak handles SAML authentication requests using the HTTP-Redirect binding. If a client is configured with a wildcard redirect URL, an attacker can craft a request that includes malicious parameters. When a user authenticates, Keycloak appends its legitimate response to the attacker's parameters. This can cause some service providers to process the attacker's data instead of the real login information, potentially leading to a user being logged into the wrong account.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
- Puntuación base: 4.7
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.33%
- Percentil entre todas las CVEs puntuadas: 24
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-20
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-18217",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-18217",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-07-31T19:32:10.362098Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "secalert@redhat.com",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 3.4,
"attackVector": "NETWORK",
"baseSeverity": "LOW",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "REQUIRED",
"attackComplexity": "HIGH",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 1.4,
"exploitabilityScore": 1.6
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 4.7,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 1.4,
"exploitabilityScore": 2.8
}
]
},
"affected": [
{
"source": "secalert@redhat.com",
"affectedData": [
{
"cpes": [
"cpe:/a:redhat:build_keycloak:"
],
"vendor": "Red Hat",
"product": "Red Hat Build of Keycloak",
"packageName": "keycloak-services",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "affected"
},
{
"cpes": [
"cpe:/a:redhat:build_keycloak:"
],
"vendor": "Red Hat",
"product": "Red Hat Build of Keycloak",
"packageName": "rhbk-keycloak-rhel9/rhbk-keycloak-rhel9",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "affected"
},
{
"cpes": [
"cpe:/a:redhat:build_keycloak:"
],
"vendor": "Red Hat",
"product": "Red Hat Build of Keycloak",
"packageName": "rhbk-openshift-rhel9/rhbk-openshift-rhel9",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "affected"
},
{
"cpes": [
"cpe:/a:redhat:jboss_data_grid:8"
],
"vendor": "Red Hat",
"product": "Red Hat Data Grid 8",
"packageName": "keycloak-services",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
},
{
"cpes": [
"cpe:/a:redhat:jbosseapxp"
],
"vendor": "Red Hat",
"product": "Red Hat JBoss Enterprise Application Platform Expansion Pack",
"packageName": "keycloak-services",
"collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html",
"defaultStatus": "unaffected"
},
{
"cpes": [
"cpe:/a:redhat:red_hat_single_sign_on:7"
],
"vendor": "Red Hat",
"product": "Red Hat Single Sign-On 7",
"packageName": "keycloak-services",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-07-31T08:16:28.037",
"references": [
{
"url": "https://access.redhat.com/security/cve/CVE-2026-18217",
"tags": [
"Vendor Advisory"
],
"source": "secalert@redhat.com"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2508311",
"tags": [
"Issue Tracking",
"Vendor Advisory"
],
"source": "secalert@redhat.com"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Secondary",
"source": "secalert@redhat.com",
"description": [
{
"lang": "en",
"value": "CWE-20"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in the SAML protocol implementation of Keycloak, an open-source identity and access management solution. The issue occurs when Keycloak handles SAML authentication requests using the HTTP-Redirect binding. If a client is configured with a wildcard redirect URL, an attacker can craft a request that includes malicious parameters. When a user authenticates, Keycloak appends its legitimate response to the attacker's parameters. This can cause some service providers to process the attacker's data instead of the real login information, potentially leading to a user being logged into the wrong account."
}
],
"lastModified": "2026-08-07T18:05:48.777",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E5C930CB-4EAD-497B-A44B-D880F2A1F85B"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "secalert@redhat.com"
}