CVE-2026-85580CWE-22path-traversal

CVE-2026-85580

Medium · published September 4, 2026

CVSS v3.1
6.5
EPSS
1%
Percentile
46.9
In the wild
Unconfirmed
What it is

SiYuan versions before v3.8.2 contain a path guard bypass vulnerability in the MCP file-access handler that uses case-sensitive matching on Linux filesystems. Attackers can read the protected publishAccess.json file by requesting case-variant paths like PublishAccess.json to disclose sensitive publish-access configuration and metadata.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
7.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
EPSS
0.00578 · 46.9th percentile
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-09-04T16:17Z
References (3)
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mmgw-3mx9-cfwp · [email protected]https://www.vulncheck.com/advisories/siyuan-before-3.8.2-path-guard-bypass-via-case-mismatch · [email protected]https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mmgw-3mx9-cfwp · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 06 SEP 03:33Z
    EPSS moved — → 1%
    epss
  • 04 SEP 11:29Z
    SiYuan before v3.8.2 Path Guard Bypass via Case Mismatch
    cvelistv5