{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-40107",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-04-09T01:41:38.536Z",
        "datePublished": "2026-04-09T21:03:58.572Z",
        "dateUpdated": "2026-04-09T21:03:58.572Z"
    },
    "containers": {
        "cna": {
            "title": "SiYuan Affected by Zero-Click NTLM Hash Theft and Blind SSRF via Mermaid Diagram Rendering",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-918",
                            "lang": "en",
                            "description": "CWE-918: Server-Side Request Forgery (SSRF)",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "NONE",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "HIGH",
                        "vulnIntegrityImpact": "NONE",
                        "vulnAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "LOW",
                        "subIntegrityImpact": "LOW",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 8.7,
                        "baseSeverity": "HIGH",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:L/SA:N",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-w95v-4h65-j455",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-w95v-4h65-j455"
                }
            ],
            "affected": [
                {
                    "vendor": "siyuan-note",
                    "product": "siyuan",
                    "versions": [
                        {
                            "version": "< 3.6.4",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-04-09T21:03:58.572Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "SiYuan is a personal knowledge management system. Prior to 3.6.4, SiYuan configures Mermaid.js with securityLevel: \"loose\" and htmlLabels: true. In this mode, <img> tags with src attributes survive Mermaid's internal DOMPurify and land in SVG <foreignObject> blocks. The SVG is injected via innerHTML with no secondary sanitization. When a victim opens a note containing a malicious Mermaid diagram, the Electron client fetches the URL. On Windows, a protocol-relative URL (//attacker.com/image.png) resolves as a UNC path (\\\\attacker.com\\image.png). Windows attempts SMB authentication automatically, sending the victim's NTLMv2 hash to the attacker. This vulnerability is fixed in 3.6.4."
                }
            ],
            "source": {
                "advisory": "GHSA-w95v-4h65-j455",
                "discovery": "UNKNOWN"
            }
        }
    }
}