RCE in Siyuan-Note Siyuan
CVE-2026-74801
SiYuan before 3.7.4 fails to properly escape workspace directory paths when constructing command-line arguments for the elevated elevator.exe helper process. Attackers can create a malicious workspace directory with command metacharacters in its path and trigger the Microsoft Defender exclusion flow to execute arbitrary commands with administrator privileges after UAC approval.
Vulnerability class: Command Injection (OS Command Injection)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (9.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 9.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.002 · change: -0.001
Affected products
- Siyuan-Note Siyuan — versions 0, 3.7.4
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-vmp7-pm7g-ghcc (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-before-local-privilege-escalation-via-eleva… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-74801?
- CVE-2026-74801 is a high-severity vulnerability in Siyuan-Note Siyuan, classified under OS Command Injection. CVSS score: 8.2/10. Published 2026-08-17.
- How severe is CVE-2026-74801?
- High severity. CVSS v3 base score is 8.2 out of 10.