CVE-2026-109309 SiYuan v3.7.0 before v3.8.6 Arbitrary File Read via Plugin ResponseFile.Path
Attackers with malicious kernel plugins can read arbitrary files, including API tokens, via path traversal in the plugin HTTP server.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-109309?
CVE-2026-109309 is a medium-severity path traversal vulnerability in siyuan-note siyuan, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
SiYuan v3.7.0 before v3.8.6 contains an absolute path traversal vulnerability in the kernel's private plugin HTTP server, which passes a kernel plugin handler's ResponseFile.Path to gin's Context.File without validation. Attackers supplying a malicious kernel plugin can return an absolute path to read any file readable by the SiYuan process, including the API token and conf.json.
Weakness: CWE-22
Which versions are affected by CVE-2026-109309?
How do I fix CVE-2026-109309?
No fix has been published for CVE-2026-109309 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-2026-109309 being exploited?
There is no known exploitation of CVE-2026-109309 in the wild and no public exploit code.
Sources
Also known as GHSA-g3cr-c99q-2hfc, GHSA-phmw-4rgv-r4xv.