OneUptime SSO: Multi-Assertion Identity Injection via Decoupled Signature Verification_CVE-2026-34840

{
    "lastseen": "",
    "description": "OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, OneUptime's SAML SSO implementation (App/FeatureSet/Identity/Utils/SSO.ts) has decoupled signature verification and identity extraction. isSignatureValid() verifies the first <Signature> element in the XML DOM using xml-crypto, while getEmail() always reads from assertion[0] via xml2js. An attacker can prepend an unsigned assertion containing an arbitrary identity before a legitimately signed assertion, resulting in authentication bypass. This issue has been patched in version 10.0.42.",
    "published": "2026-04-02T18:52:48.274Z",
    "modified": "2026-04-02T20:20:13.291Z",
    "type": "cve",
    "title": "OneUptime SSO: Multi-Assertion Identity Injection via Decoupled Signature Verification",
    "source": "GitHub_M",
    "references": "https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g\nhttps://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1\nhttps://github.com/OneUptime/oneuptime/releases/tag/10.0.42",
    "id": "CVE-2026-34840",
    "bulletinFamily": "",
    "cwe": [
        "CWE-347"
    ],
    "cvelist": null,
    "sourceData": "OneUptime oneuptime < 10.0.42",
    "sourceHref": "",
    "cvss": {
        "score": 8.1,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
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        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "oneuptime",
    "version": "< 10.0.42",
    "vendor": "OneUptime",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}