---
cve: "CVE-2026-100643"
severity: "HIGH"
cvss: 8.5
epss: "0.4%"
vendor: "siyuan-note"
kev: false
exploited: false
published: "2026-09-26 13:23:15"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-30T06:27:36+02:00"
---

# CVE-2026-100643

> 8.5 HIGH · 🧪 PoC

## Beschreibung

SiYuan versions before v3.8.4 fail to properly escape four stored Attribute View values in textarea elements, allowing authenticated attackers to inject JavaScript by modifying field descriptions, template sources, select option descriptions, or footer calculation templates. Attackers can execute stored JavaScript when other users open affected database menus, and in the Electron desktop app with nodeIntegration enabled, this leads to command execution with SiYuan process privileges.

## CNA-Record (Kanon, cvelistV5)

- CNA: **VulnCheck**
- State: PUBLISHED
- Stand: 2026-09-28 18:32:45
- CNA-CVSS: **8.5** (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **no**
  - Technical Impact: **total**

## CVSS-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |

## Patch verfügbar (OSV)

- 9f775e8a12daef8255556097396f9b2739078892 (Commit)

## Referenzen

- <https://github.com/siyuan-note/siyuan/security/advisories/GHSA-h3p6-c22r-fx2j>
- <https://www.vulncheck.com/advisories/siyuan-before-3.8.4-stored-xss-via-attribute-view-textarea>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-100643) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_