Vulnerability · Published Sep 4, 2026 · Assigned by VulnCheck
CVE-2026-85580SiYuan before v3.8.2 Path Guard Bypass via Case Mismatch
Medium 6.5
In plain English
A medium-severity path traversal in siyuan from siyuan-note. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities).
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.6%top 52.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| siyuan-note | siyuan | 0 – before 3.8.2 |
Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
References
- GitHub Security Advisory (GHSA-mmgw-3mx9-cfwp) vendor-advisory
- VulnCheck Advisory: SiYuan before v3.8.2 Path Guard Bypass via Case Mismatch third-party-advisory