SimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification_CVE-2026-48558

{
    "lastseen": "",
    "description": "SimpleHelp versions 5.5.15 and prior and 6.0 pre-release versions contain an authentication bypass vulnerability in the OIDC authentication flow. When OIDC authentication is configured, identity tokens submitted during login are accepted without verifying their cryptographic signature. In a vulnerable configuration, a remote, unauthenticated attacker can submit a forged token containing arbitrary identity claims to obtain a fully authenticated technician session. In some configurations, this may also allow bypass of multi-factor authentication. No user interaction is required.",
    "published": "2026-06-12T17:07:05.453Z",
    "modified": "2026-06-12T18:47:10.290Z",
    "type": "cve",
    "title": "SimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification",
    "source": "VulnCheck",
    "references": "https://horizon3.ai/attack-research/disclosures/cve-2026-48558-simplehelp-authentication-bypass-iocs/\nhttps://simple-help.com/security/simplehelp-security-update-2026-05\nhttps://simple-help.com/release-news",
    "id": "CVE-2026-48558",
    "bulletinFamily": "",
    "cwe": [
        "CWE-347"
    ],
    "cvelist": null,
    "sourceData": "SimpleHelp SimpleHelp 5.5.0\nSimpleHelp SimpleHelp 6.0",
    "sourceHref": "",
    "cvss": {
        "score": 9.5,
        "severity": "CRITICAL",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "SimpleHelp",
    "version": "5.5.0",
    "vendor": "SimpleHelp",
    "ai_description": "Authentication bypass vulnerability in OIDC authentication flow due to missing JWT signature verification, allowing remote attackers to obtain fully authenticated sessions",
    "ai_severity": "Critical",
    "ai_vendor": "SimpleHelp",
    "ai_product": "SimpleHelp",
    "ai_version": "5.5.15 and prior, 6.0 pre-release",
    "ai_score": 9.5
}