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    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-126265",
        "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "state": "PUBLISHED",
        "assignerShortName": "VulnCheck",
        "dateReserved": "2026-11-10T20:13:22.556Z",
        "datePublished": "2026-11-13T09:36:50.432Z",
        "dateUpdated": "2026-11-13T09:36:50.432Z"
    },
    "containers": {
        "cna": {
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                "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
                "shortName": "VulnCheck",
                "dateUpdated": "2026-11-13T09:36:50.432Z"
            },
            "datePublic": "2026-10-26T00:00:00.000Z",
            "title": "SiYuan 2.1.0 before 3.8.9 CAPTCHA Bypass via Stale Login Cookie",
            "descriptions": [
                {
                    "lang": "en",
                    "value": "SiYuan 2.1.0 before 3.8.9 contains a flaw where the loginAuth CAPTCHA challenge lives in a signed client-side cookie, allowing reuse of a solved challenge. Attackers can replay the original signed siyuan cookie with distinct wrong access codes to brute-force the code and gain an administrator session."
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "description": "Improper Restriction of Excessive Authentication Attempts",
                            "cweId": "CWE-307",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "vendor": "siyuan-note",
                    "product": "siyuan",
                    "defaultStatus": "unaffected",
                    "packageURL": "pkg:golang/github.com/siyuan-note/siyuan/kernel",
                    "versions": [
                        {
                            "version": "2.1.0",
                            "status": "affected",
                            "versionType": "semver",
                            "lessThan": "3.8.9"
                        },
                        {
                            "version": "3.8.9",
                            "status": "unaffected",
                            "versionType": "semver"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
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                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.1.0",
                                    "versionEndExcluding": "3.8.9"
                                }
                            ]
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "format": "CVSS",
                    "cvssV4_0": {
                        "version": "4.0",
                        "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
                        "attackVector": "NETWORK",
                        "attackComplexity": "HIGH",
                        "attackRequirements": "PRESENT",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "HIGH",
                        "vulnIntegrityImpact": "HIGH",
                        "vulnAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 9.1,
                        "baseSeverity": "CRITICAL"
                    }
                },
                {
                    "format": "CVSS",
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
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                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "scope": "UNCHANGED",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "HIGH",
                        "availabilityImpact": "NONE",
                        "baseScore": 7.4,
                        "baseSeverity": "HIGH"
                    }
                }
            ],
            "references": [
                {
                    "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-23g4-vqq8-5764",
                    "tags": [
                        "vendor-advisory"
                    ],
                    "name": "GitHub Security Advisory (GHSA-23g4-vqq8-5764)"
                },
                {
                    "name": "VulnCheck Advisory: SiYuan 2.1.0 before 3.8.9 CAPTCHA Bypass via Stale Login Cookie",
                    "tags": [
                        "third-party-advisory"
                    ],
                    "url": "https://www.vulncheck.com/advisories/siyuan-2.1.0-before-3.8.9-captcha-bypass-via-stale-login-cookie"
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "value": "rexpository",
                    "type": "reporter"
                }
            ],
            "x_generator": {
                "engine": "vulncheck-endgame"
            }
        }
    }
}