CVE-2026-85580 SiYuan before v3.8.2 Path Guard Bypass via Case Mismatch
Attackers can bypass path guards to read sensitive configuration files in SiYuan by exploiting case-sensitive filesystem matching.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-85580?
CVE-2026-85580 is a high-severity path traversal vulnerability in siyuan-note siyuan, published on 4 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Weakness: CWE-22
Which versions are affected by CVE-2026-85580?
How do I fix CVE-2026-85580?
No fix has been published for CVE-2026-85580 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-85580 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85580 exists.
Sources
Also known as GHSA-gwmf-gvp9-fcc2, GHSA-mmgw-3mx9-cfwp.