Vulnerability-Lookup

CVE-2026-66395 (GCVE-0-2026-66395)

Vulnerability from cvelistv5 – Published: 2026-07-27 15:43 – Updated: 2026-07-27 16:23

Title

SiYuan Desktop before v3.7.2 Reflected XSS to RCE via siyuan Protocol

Summary

SiYuan desktop before v3.7.2 contains a reflected cross-site scripting vulnerability in the bazaar plugin readme handler that allows attackers to execute arbitrary code by crafting a malicious siyuan:// deep link. Attackers can inject HTML payloads via the plugin name parameter that execute with full Node.js access through insertAdjacentHTML rendering in an insecurely configured Electron renderer.

Severity

9.4 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

9.6 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Assigner

VulnCheck

References

2 references

URL	Tags
https://github.com/siyuan-note/siyuan/security/ad…	vendor-advisory
https://www.vulncheck.com/advisories/siyuan-deskt…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
siyuan-note	siyuan	Affected: 0 , < 3.7.2 (semver) Unaffected: 3.7.2 (semver)

Date Public

2026-07-13 00:00

Credits

hypnguyen1209

Show details on NVD website

JSON

To clipboard

{
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    "adp": [
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                "id": "CVE-2026-66395",
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                    "Exploitation": "poc"
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                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-27T16:23:27.484277Z",
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        "title": "CISA ADP Vulnrichment"
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      "metrics": [
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            "attackComplexity": "LOW",
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            "baseScore": 9.6,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
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      "problemTypes": [
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          "descriptions": [
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              "cweId": "CWE-79",
              "description": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
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              "type": "CWE"
            }
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      "providerMetadata": {
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        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
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          "name": "GitHub Security Advisory (GHSA-6gx2-8gcr-x83f)",
          "tags": [
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          ],
          "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-6gx2-8gcr-x83f"
        },
        {
          "name": "VulnCheck Advisory: SiYuan Desktop before v3.7.2 Reflected XSS to RCE via siyuan Protocol",
          "tags": [
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          "url": "https://www.vulncheck.com/advisories/siyuan-desktop-before-reflected-xss-to-rce-via-siyuan-protocol"
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      ],
      "title": "SiYuan Desktop before v3.7.2 Reflected XSS to RCE via siyuan Protocol",
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  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-66395",
    "datePublished": "2026-07-27T15:43:46.073Z",
    "dateReserved": "2026-07-26T12:22:34.139Z",
    "dateUpdated": "2026-07-27T16:23:32.228Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
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  "vulnerability-lookup:meta": {
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  }
}

GHSA-X52J-M89G-WH64

Vulnerability from github – Published: 2026-07-27 18:31 – Updated: 2026-07-27 18:31

Details

Severity

9.6 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

9.4 (Critical)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-66395"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-27T16:18:12Z",
    "severity": "CRITICAL"
  },
  "details": "SiYuan desktop before v3.7.2 contains a reflected cross-site scripting vulnerability in the bazaar plugin readme handler that allows attackers to execute arbitrary code by crafting a malicious siyuan:// deep link. Attackers can inject HTML payloads via the plugin name parameter that execute with full Node.js access through insertAdjacentHTML rendering in an insecurely configured Electron renderer.",
  "id": "GHSA-x52j-m89g-wh64",
  "modified": "2026-07-27T18:31:49Z",
  "published": "2026-07-27T18:31:49Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-6gx2-8gcr-x83f"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-66395"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/siyuan-desktop-before-reflected-xss-to-rce-via-siyuan-protocol"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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",
      "type": "CVSS_V4"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

CVE-2026-66395 (GCVE-0-2026-66395)

GHSA-X52J-M89G-WH64

Tags

Sightings

Nomenclature