CVE-2026-82649 SiYuan before 3.8.1 Local Privilege Escalation via Uncontrolled Search Path
Local attackers can escalate privileges by placing malicious executables in the installer directory, exploiting uncontrolled search paths in the Windows installer.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-82649?
CVE-2026-82649 is a high-severity path traversal vulnerability in siyuan-note siyuan, published on 30 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
SiYuan Windows installer before version 3.8.1 (affected versions >= 2.0.14) contains an uncontrolled search path element vulnerability in its NSIS installer, which invokes system executables such as TASKKILL by name rather than by absolute path. Because NSIS nsExec::Exec resolves these calls using a search path that includes the installer's own launch directory ahead of System32, an attacker who plants a malicious executable (e.g., a renamed TASKKILL.exe) in that directory can have it executed when the installer runs. These calls occur in electron-builder's preInit hook before the license page is displayed, and with an all-users (elevated) install the planted binary executes with an elevated token, resulting in local privilege escalation.
Weakness: CWE-427
Which versions are affected by CVE-2026-82649?
How do I fix CVE-2026-82649?
No fix has been published for CVE-2026-82649 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-2026-82649 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82649 exists.
Sources
Also known as GHSA-9j65-967f-5rv3, GHSA-jrgp-6vq3-j6hp.