---
id: CVE-2026-85579
title: >-
  SiYuan is affected by an information disclosure vulnerability (confirmed in
  v3.8.1, fixed in v3.8.2) in the reader-accessible POST
  /api/transactions/undoState endpoint
summary: >-
  SiYuan is affected by an information disclosure vulnerability (confirmed in
  v3.8.1, fixed in v3.8.2) in the reader-accessible POST
  /api/transactions/undoState endpoint. The endpoint returns the
  peekMutatedRootIDs list from the global und…
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-639
vendor: siyuan-note
product: siyuan
affected:
  - siyuan < 3.8.2
published: '2026-09-04'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T20:05:53.177'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-85579'
references:
  - url: >-
      https://github.com/siyuan-note/siyuan/security/advisories/GHSA-6gf8-q9ch-w732
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/siyuan-before-3.8.2-information-disclosure-via-undostate
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/siyuan-note/siyuan/security/advisories/GHSA-6gf8-q9ch-w732
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
epss: 0.00204
epssPercentile: 0.10744
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-08T14:42:19.869849Z'
ingestedAt: '2026-09-08T15:33:26.960Z'
---

## Overview

SiYuan is affected by an information disclosure vulnerability (confirmed in v3.8.1, fixed in v3.8.2) in the reader-accessible POST /api/transactions/undoState endpoint. The endpoint returns the peekMutatedRootIDs list from the global undo-log stack for a caller-supplied root ID without applying publish-access visibility filtering. An authenticated reader who knows the root ID of a visible document can obtain the internal root IDs of other documents (including private or unpublished ones) modified in the same cross-document transaction, disclosing internal identifiers and cross-document relationships. Document body contents are not directly exposed.

## Remediation

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