---
cve: "CVE-2026-85584"
severity: "HIGH"
cvss: 8.7
epss: "0.3%"
vendor: "siyuan-note"
kev: false
exploited: false
published: "2026-09-04 12:17:20"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-28T15:30:52+02:00"
---

# CVE-2026-85584

> 8.7 HIGH · 🧪 PoC

## Beschreibung

SiYuan versions before v3.8.2 contain a denial of service vulnerability in the publish-service Basic Auth throttle that stores failed-attempt state using attacker-controlled usernames without enforcing capacity limits or eviction policies. Unauthenticated attackers can submit repeated authentication requests with unique invalid usernames to exhaust memory and increase synchronization overhead, degrading service availability.

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **yes**
  - Technical Impact: **partial**

## CVSS-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 44a6c212a994c7ba8129fc38b001a9ab58957c6f (Commit)

## Referenzen

- <https://github.com/siyuan-note/siyuan/security/advisories/GHSA-2x7j-p79w-7744>
- <https://www.vulncheck.com/advisories/siyuan-before-3.8.2-denial-of-service-via-auth-throttle>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-85584) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_