Org.keycloak/keycloak-quarkus-server: keycloak: proxy bypass due to improper handling of matrix parameters in url paths_CVE-2026-0976

{
    "lastseen": "",
    "description": "A flaw was found in Keycloak. This improper input validation vulnerability occurs because Keycloak accepts RFC-compliant matrix parameters in URL path segments, while common reverse proxy configurations may ignore or mishandle them. A remote attacker can craft requests to mask path segments, potentially bypassing proxy-level path filtering. This could expose administrative or sensitive endpoints that operators believe are not externally reachable.",
    "published": "2026-01-15T12:06:21.251Z",
    "modified": "2026-01-15T12:06:21.251Z",
    "type": "cve",
    "title": "Org.keycloak/keycloak-quarkus-server: keycloak: proxy bypass due to improper handling of matrix parameters in url paths",
    "source": "redhat",
    "references": "https://access.redhat.com/security/cve/CVE-2026-0976\nhttps://bugzilla.redhat.com/show_bug.cgi?id=2429869",
    "id": "CVE-2026-0976",
    "bulletinFamily": "",
    "cwe": [
        "CWE-20"
    ],
    "cvelist": null,
    "sourceData": "",
    "sourceHref": "",
    "cvss": {
        "score": 3.7,
        "severity": "LOW",
        "vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
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        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
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            "baseScore": 0,
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    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Red Hat Build of Keycloak",
    "version": "",
    "vendor": "Red Hat",
    "ai_description": "",
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    "ai_score": 0
}