CVE-2026-75916 (GCVE-0-2026-75916)

Vulnerability from cvelistv5 – Published: 2026-08-19 14:01 – Updated: 2026-08-19 14:01
VLAI
Title
SiYuan XSS-to-RCE via unescaped block metadata in hint popup
Summary
SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block's name, alias, and memo fields are concatenated into the popup's HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. <img src=x onerror=...>) that executes automatically when a victim types '((' followed by a search term that surfaces the crafted block. Because SiYuan's Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require('child_process') access, allowing the XSS to escalate to arbitrary OS command execution.
Severity
9.3 (Critical)
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
8.6 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
Impacted products
Vendor Product Version CPE status
siyuan-note siyuan     cpe:2.3:a:b3log:siyuan:-:*:*:*:*:*:*:*
Create a notification for this product.
Date Public
2026-08-05 00:00
Credits
alham-rizvi hey-raghav
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "affected",
          "packageURL": "pkg:npm/siyuan",
          "product": "siyuan",
          "vendor": "siyuan-note"
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:b3log:siyuan:-:*:*:*:*:*:*:*",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "alham-rizvi"
        },
        {
          "lang": "en",
          "type": "analyst",
          "value": "hey-raghav"
        }
      ],
      "datePublic": "2026-08-05T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the \u0027((\u0027 block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block\u0027s name, alias, and memo fields are concatenated into the popup\u0027s HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. \u003cimg src=x onerror=...\u003e) that executes automatically when a victim types \u0027((\u0027 followed by a search term that surfaces the crafted block. Because SiYuan\u0027s Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require(\u0027child_process\u0027) access, allowing the XSS to escalate to arbitrary OS command execution."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "LOCAL",
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "HIGH",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "HIGH",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH"
          },
          "format": "CVSS"
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 8.6,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-19T14:01:50.370Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "GitHub Security Advisory (GHSA-5prr-vgxq-69g9)",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-5prr-vgxq-69g9"
        },
        {
          "name": "VulnCheck Advisory: SiYuan XSS-to-RCE via unescaped block metadata in hint popup",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/siyuan-xss-to-rce-via-unescaped-block-metadata-in-hint-popup"
        }
      ],
      "title": "SiYuan XSS-to-RCE via unescaped block metadata in hint popup",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-75916",
    "datePublished": "2026-08-19T14:01:50.370Z",
    "dateReserved": "2026-08-18T15:05:54.226Z",
    "dateUpdated": "2026-08-19T14:01:50.370Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-75916",
      "date": "2026-08-20",
      "epss": "0.00159",
      "percentile": "0.05591"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-75916\",\"sourceIdentifier\":\"disclosure@vulncheck.com\",\"published\":\"2026-08-19T14:17:41.687\",\"lastModified\":\"2026-08-19T14:17:41.687\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the \u0027((\u0027 block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block\u0027s name, alias, and memo fields are concatenated into the popup\u0027s HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. \u003cimg src=x onerror=...\u003e) that executes automatically when a victim types \u0027((\u0027 followed by a search term that surfaces the crafted block. Because SiYuan\u0027s Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require(\u0027child_process\u0027) access, allowing the XSS to escalate to arbitrary OS command execution.\"}],\"affected\":[{\"source\":\"disclosure@vulncheck.com\",\"affectedData\":[{\"vendor\":\"siyuan-note\",\"product\":\"siyuan\",\"defaultStatus\":\"affected\",\"packageURL\":\"pkg:npm/siyuan\"}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"disclosure@vulncheck.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:L/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\",\"baseScore\":9.3,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"PASSIVE\",\"vulnConfidentialityImpact\":\"HIGH\",\"vulnIntegrityImpact\":\"HIGH\",\"vulnAvailabilityImpact\":\"HIGH\",\"subConfidentialityImpact\":\"HIGH\",\"subIntegrityImpact\":\"HIGH\",\"subAvailabilityImpact\":\"HIGH\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"disclosure@vulncheck.com\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H\",\"baseScore\":8.6,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":6.0}]},\"weaknesses\":[{\"source\":\"disclosure@vulncheck.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-79\"}]}],\"references\":[{\"url\":\"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-5prr-vgxq-69g9\",\"source\":\"disclosure@vulncheck.com\"},{\"url\":\"https://www.vulncheck.com/advisories/siyuan-xss-to-rce-via-unescaped-block-metadata-in-hint-popup\",\"source\":\"disclosure@vulncheck.com\"}]}}"
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.