CVE-2026-86712

SiYuan before 3.8.2 trusts the attacker-writable text/siyuan clipboard MIME type and skips sanitization in the paste handler, allowing code execution in the Node-enabled desktop renderer. Attackers can craft malicious web pages that write to the clipboard, and when pasted into SiYuan, injected scripts execute with full Node.js access through the Electron main process.

CVSS v3 8.8 HIGH

8.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/siyuan-note/siyuan
https://github.com/siyuan-note/siyuan/blob/v3.8.1/app/src/protyle/util/paste.ts
https://github.com/siyuan-note/siyuan/commit/9ce660652de2ced26ec2d98a5a242cb0b8bb7273
https://github.com/siyuan-note/siyuan/releases/tag/v3.8.2
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-9rr9-pxr4-gcgc
https://www.vulncheck.com/advisories/siyuan-before-3.8.2-remote-code-execution-via-clipboard

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-08 12:16

Updated : 2026-09-10 16:18

NVD link : CVE-2026-86712

Mitre link : CVE-2026-86712

CVE.ORG link : CVE-2026-86712

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

{"id": "CVE-2026-86712", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-86712", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-09-10T14:27:43.598618Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.8}], "cvssMetricV40": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.6, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "ACTIVE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "disclosure@vulncheck.com", "affectedData": [{"repo": "https://github.com/siyuan-note/siyuan", "vendor": "siyuan-note", "product": "siyuan", "versions": [{"status": "affected", "version": "0", "lessThan": "3.8.2", "versionType": "semver"}], "packageURL": "pkg:github/siyuan-note/siyuan", "collectionURL": "https://github.com/siyuan-note/siyuan", "defaultStatus": "unaffected"}]}], "published": "2026-09-08T12:16:59.990", "references": [{"url": "https://github.com/siyuan-note/siyuan", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/siyuan-note/siyuan/blob/v3.8.1/app/src/protyle/util/paste.ts", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/siyuan-note/siyuan/commit/9ce660652de2ced26ec2d98a5a242cb0b8bb7273", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/siyuan-note/siyuan/releases/tag/v3.8.2", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-9rr9-pxr4-gcgc", "source": "disclosure@vulncheck.com"}, {"url": "https://www.vulncheck.com/advisories/siyuan-before-3.8.2-remote-code-execution-via-clipboard", "source": "disclosure@vulncheck.com"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "description": [{"lang": "en", "value": "CWE-79"}]}], "descriptions": [{"lang": "en", "value": "SiYuan before 3.8.2 trusts the attacker-writable text/siyuan clipboard MIME type and skips sanitization in the paste handler, allowing code execution in the Node-enabled desktop renderer. Attackers can craft malicious web pages that write to the clipboard, and when pasted into SiYuan, injected scripts execute with full Node.js access through the Electron main process."}], "lastModified": "2026-09-10T16:18:03.470", "sourceIdentifier": "disclosure@vulncheck.com"}