Vulnerability-Lookup

GHSA-962C-HGX6-FFMX

Vulnerability from github – Published: 2026-08-19 15:32 – Updated: 2026-08-19 15:32

Details

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. ) 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

8.6 (High)


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

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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-75916"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-19T14:17:41Z",
    "severity": "CRITICAL"
  },
  "details": "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.",
  "id": "GHSA-962c-hgx6-ffmx",
  "modified": "2026-08-19T15:32:28Z",
  "published": "2026-08-19T15:32:28Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-5prr-vgxq-69g9"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-75916"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/siyuan-xss-to-rce-via-unescaped-block-metadata-in-hint-popup"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "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",
      "type": "CVSS_V4"
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}

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

Vulnerability from cvelistv5 – Published: 2026-08-19 14:01 – Updated: 2026-08-21 19:22

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

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-21 19:21 UTC

CWE

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

Assigner

VulnCheck mitre root

References

2 references

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

Impacted products

1 product

Vendor	Product	Version
siyuan-note	siyuan	cpe:2.3:a:b3log:siyuan:-:::::::*

Date Public

2026-08-05 00:00

Credits

alham-rizvi hey-raghav

Show details on NVD website

JSON

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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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.