---
id: CVE-2026-85581
title: >-
  SiYuan before v3.8.2 contains a denial of service vulnerability in the
  unauthenticated /api/system/uiproc endpoint that accepts and retains
  attacker-controlled process identifiers without size limits or authentication
summary: >-
  SiYuan before v3.8.2 contains a denial of service vulnerability in the
  unauthenticated /api/system/uiproc endpoint that accepts and retains
  attacker-controlled process identifiers without size limits or authentication.
  Attackers can send…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-770
vendor: siyuan-note
product: siyuan
affected:
  - siyuan < 3.8.2
published: '2026-09-04'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T16:17:59.087'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-85581'
references:
  - url: >-
      https://github.com/siyuan-note/siyuan/security/advisories/GHSA-wv96-wmf5-xvj2
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/siyuan-before-3.8.2-denial-of-service-via-unauthenticated-ui-process-registration
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-10T14:23:07.702339Z'
epss: 0.00318
epssPercentile: 0.24932
ingestedAt: '2026-09-08T20:10:03.164Z'
---

## Overview

SiYuan before v3.8.2 contains a denial of service vulnerability in the unauthenticated /api/system/uiproc endpoint that accepts and retains attacker-controlled process identifiers without size limits or authentication. Attackers can send repeated requests with unique identifiers to exhaust process memory and degrade service availability.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.