---
id: CVE-2026-77086
title: >-
  SiYuan before v3.7.4 fails to validate the packageName parameter in Bazaar
  install and uninstall endpoints, allowing authenticated administrators to
  perform path traversal via directory traversal sequences
summary: >-
  SiYuan before v3.7.4 fails to validate the packageName parameter in Bazaar
  install and uninstall endpoints, allowing authenticated administrators to
  perform path traversal via directory traversal sequences. Attackers with admin
  access ca…
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-22
vendor: siyuan-note
product: siyuan
affected:
  - siyuan < 3.7.4
published: '2026-08-21'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:10:00.103'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77086'
references:
  - url: >-
      https://github.com/siyuan-note/siyuan/security/advisories/GHSA-wr4w-7vjm-mmx3
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/siyuan-before-path-traversal-via-packagename
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
epss: 0.01028
epssPercentile: 0.6348
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-08-21T11:45:56.651260Z'
ingestedAt: '2026-10-01T15:48:17.846Z'
---

## Overview

SiYuan before v3.7.4 fails to validate the packageName parameter in Bazaar install and uninstall endpoints, allowing authenticated administrators to perform path traversal via directory traversal sequences. Attackers with admin access can write arbitrary files to any location via install operations or recursively delete directories via uninstall operations by supplying crafted packageName values.

## Remediation

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